[Docs] Fix the go client docs missing in website (apache#5595)

Signed-off-by: xiaolong.ran <[email protected]>

Fixes: apache#2719 

### Motivation

In website, the go client docs missing.

### Modifications

Add missing docs for go client.

site2/docs/client-libraries-go.md

@@ -123,7 +123,7 @@ msg := pulsar.ProducerMessage{
     Payload: []byte("Hello, Pulsar"),
 }
 
-if err := producer.Send(msg); err != nil {
+if err := producer.Send(context.Background(), msg); err != nil {
     log.Fatalf("Producer could not send message: %v", err)
 }
 ```
@@ -140,9 +140,14 @@ Method | Description | Return type
 :------|:------------|:-----------
 `Topic()` | Fetches the producer's [topic](reference-terminology.md#topic)| `string`
 `Name()` | Fetches the producer's name | `string`
-`Send(context.Context, ProducerMessage) error` | Publishes a [message](#messages) to the producer's topic. This call will block until the message is successfully acknowledged by the Pulsar broker, or an error will be thrown if the timeout set using the `SendTimeout` in the producer's [configuration](#producer-configuration) is exceeded. | `error`
+`Send(context.Context, ProducerMessage)` | Publishes a [message](#messages) to the producer's topic. This call will block until the message is successfully acknowledged by the Pulsar broker, or an error will be thrown if the timeout set using the `SendTimeout` in the producer's [configuration](#producer-configuration) is exceeded. | `error`
+`SendAndGetMsgID(context.Context, ProducerMessage)`| Send a message, this call will be blocking until is successfully acknowledged by the Pulsar broker. | (MessageID, error)
 `SendAsync(context.Context, ProducerMessage, func(ProducerMessage, error))` | Publishes a [message](#messages) to the producer's topic asynchronously. The third argument is a callback function that specifies what happens either when the message is acknowledged or an error is thrown. |
+`SendAndGetMsgIDAsync(context.Context, ProducerMessage, func(MessageID, error))`| Send a message in asynchronous mode. The callback will report back the message being published and the eventual error in publishing | 
+`LastSequenceID()` | Get the last sequence id that was published by this producer. his represent either the automatically assigned or custom sequence id (set on the ProducerMessage) that was published and acknowledged by the broker. | int64
+`Flush()`| Flush all the messages buffered in the client and wait until all messages have been successfully persisted. | error
 `Close()` | Closes the producer and releases all resources allocated to it. If `Close()` is called then no more messages will be accepted from the publisher. This method will block until all pending publish requests have been persisted by Pulsar. If an error is thrown, no pending writes will be retried. | `error`
+`Schema()` | | Schema
 
 Here's a more involved example usage of a producer:
 
@@ -205,14 +210,18 @@ Parameter | Description | Default
 :---------|:------------|:-------
 `Topic` | The Pulsar [topic](reference-terminology.md#topic) to which the producer will publish messages |
 `Name` | A name for the producer. If you don't explicitly assign a name, Pulsar will automatically generate a globally unique name that you can access later using the `Name()` method.  If you choose to explicitly assign a name, it will need to be unique across *all* Pulsar clusters, otherwise the creation operation will throw an error. |
+`Properties`| Attach a set of application defined properties to the producer. This properties will be visible in the topic stats | 
 `SendTimeout` | When publishing a message to a topic, the producer will wait for an acknowledgment from the responsible Pulsar [broker](reference-terminology.md#broker). If a message is not acknowledged within the threshold set by this parameter, an error will be thrown. If you set `SendTimeout` to -1, the timeout will be set to infinity (and thus removed). Removing the send timeout is recommended when using Pulsar's [message de-duplication](cookbooks-deduplication.md) feature. | 30 seconds
 `MaxPendingMessages` | The maximum size of the queue holding pending messages (i.e. messages waiting to receive an acknowledgment from the [broker](reference-terminology.md#broker)). By default, when the queue is full all calls to the `Send` and `SendAsync` methods will fail *unless* `BlockIfQueueFull` is set to `true`. |
-`MaxPendingMessagesAcrossPartitions` | |
+`MaxPendingMessagesAcrossPartitions` | Set the number of max pending messages across all the partitions. This setting will be used to lower the max pending messages for each partition `MaxPendingMessages(int)`, if the total exceeds the configured value.|
 `BlockIfQueueFull` | If set to `true`, the producer's `Send` and `SendAsync` methods will block when the outgoing message queue is full rather than failing and throwing an error (the size of that queue is dictated by the `MaxPendingMessages` parameter); if set to `false` (the default), `Send` and `SendAsync` operations will fail and throw a `ProducerQueueIsFullError` when the queue is full. | `false`
 `MessageRoutingMode` | The message routing logic (for producers on [partitioned topics](concepts-architecture-overview.md#partitioned-topics)). This logic is applied only when no key is set on messages. The available options are: round robin (`pulsar.RoundRobinDistribution`, the default), publishing all messages to a single partition (`pulsar.UseSinglePartition`), or a custom partitioning scheme (`pulsar.CustomPartition`). | `pulsar.RoundRobinDistribution`
 `HashingScheme` | The hashing function that determines the partition on which a particular message is published (partitioned topics only). The available options are: `pulsar.JavaStringHash` (the equivalent of `String.hashCode()` in Java), `pulsar.Murmur3_32Hash` (applies the [Murmur3](https://en.wikipedia.org/wiki/MurmurHash) hashing function), or `pulsar.BoostHash` (applies the hashing function from C++'s [Boost](https://www.boost.org/doc/libs/1_62_0/doc/html/hash.html) library) | `pulsar.JavaStringHash`
 `CompressionType` | The message data compression type used by the producer. The available options are [`LZ4`](https://github.com/lz4/lz4), [`ZLIB`](https://zlib.net/), [`ZSTD`](https://facebook.github.io/zstd/) and [`SNAPPY`](https://google.github.io/snappy/). | No compression
 `MessageRouter` | By default, Pulsar uses a round-robin routing scheme for [partitioned topics](cookbooks-partitioned.md). The `MessageRouter` parameter enables you to specify custom routing logic via a function that takes the Pulsar message and topic metadata as an argument and returns an integer (where the ), i.e. a function signature of `func(Message, TopicMetadata) int`. |
+`Batching` | Control whether automatic batching of messages is enabled for the producer. | false
+`BatchingMaxPublishDelay` | Set the time period within which the messages sent will be batched (default: 10ms) if batch messages are enabled. If set to a non zero value, messages will be queued until this time interval or until | 10ms
+`BatchingMaxMessages` | Set the maximum number of messages permitted in a batch. (default: 1000) If set to a value greater than 1, messages will be queued until this threshold is reached or batch interval has elapsed | 1000
 
 ## Consumers
 
@@ -263,10 +272,12 @@ Method | Description | Return type
 `Ack(Message)` | [Acknowledges](reference-terminology.md#acknowledgment-ack) a message to the Pulsar [broker](reference-terminology.md#broker) | `error`
 `AckID(MessageID)` | [Acknowledges](reference-terminology.md#acknowledgment-ack) a message to the Pulsar [broker](reference-terminology.md#broker) by message ID | `error`
 `AckCumulative(Message)` | [Acknowledges](reference-terminology.md#acknowledgment-ack) *all* the messages in the stream, up to and including the specified message. The `AckCumulative` method will block until the ack has been sent to the broker. After that, the messages will *not* be redelivered to the consumer. Cumulative acking can only be used with a [shared](concepts-messaging.md#shared) subscription type. | `error`
+`AckCumulativeID(MessageID)` |Ack the reception of all the messages in the stream up to (and including) the provided message. This method will block until the acknowledge has been sent to the broker. After that, the messages will not be re-delivered to this consumer. | error
 `Nack(Message)` | Acknowledge the failure to process a single message. | `error`
 `NackID(MessageID)` | Acknowledge the failure to process a single message. | `error`
 `Close()` | Closes the consumer, disabling its ability to receive messages from the broker | `error`
 `RedeliverUnackedMessages()` | Redelivers *all* unacknowledged messages on the topic. In [failover](concepts-messaging.md#failover) mode, this request is ignored if the consumer isn't active on the specified topic; in [shared](concepts-messaging.md#shared) mode, redelivered messages are distributed across all consumers connected to the topic. **Note**: this is a *non-blocking* operation that doesn't throw an error. |
+`Seek(msgID MessageID)` | Reset the subscription associated with this consumer to a specific message id. The message id can either be a specific message or represent the first or last messages in the topic. | error
 
 #### Receive example
 
@@ -325,14 +336,19 @@ func main() {
 Parameter | Description | Default
 :---------|:------------|:-------
 `Topic` | The Pulsar [topic](reference-terminology.md#topic) on which the consumer will establish a subscription and listen for messages |
+`Topics` | Specify a list of topics this consumer will subscribe on. Either a topic, a list of topics or a topics pattern are required when subscribing |
+`TopicsPattern` | Specify a regular expression to subscribe to multiple topics under the same namespace. Either a topic, a list of topics or a topics pattern are required when subscribing |
 `SubscriptionName` | The subscription name for this consumer |
+`Properties` | Attach a set of application defined properties to the consumer. This properties will be visible in the topic stats|
 `Name` | The name of the consumer |
-`AckTimeout` | | 0
+`AckTimeout` | Set the timeout for unacked messages | 0
 `NackRedeliveryDelay` | The delay after which to redeliver the messages that failed to be processed. Default is 1min. (See `Consumer.Nack()`) | 1 minute
 `Type` | Available options are `Exclusive`, `Shared`, and `Failover` | `Exclusive`
+`SubscriptionInitPos` | InitialPosition at which the cursor will be set when subscribe | Latest
 `MessageChannel` | The Go channel used by the consumer. Messages that arrive from the Pulsar topic(s) will be passed to this channel. |
 `ReceiverQueueSize` | Sets the size of the consumer's receiver queue, i.e. the number of messages that can be accumulated by the consumer before the application calls `Receive`. A value higher than the default of 1000 could increase consumer throughput, though at the expense of more memory utilization. | 1000
 `MaxTotalReceiverQueueSizeAcrossPartitions` |Set the max total receiver queue size across partitions. This setting will be used to reduce the receiver queue size for individual partitions if the total exceeds this value | 50000
+`ReadCompacted` | If enabled, the consumer will read messages from the compacted topic rather than reading the full message backlog of the topic. This means that, if the topic has been compacted, the consumer will only see the latest value for each key in the topic, up until the point in the topic message backlog that has been compacted. Beyond that point, the messages will be sent as normal. |
 
 ## Readers
 
@@ -357,6 +373,7 @@ Method | Description | Return type
 :------|:------------|:-----------
 `Topic()` | Returns the reader's [topic](reference-terminology.md#topic) | `string`
 `Next(context.Context)` | Receives the next message on the topic (analogous to the `Receive` method for [consumers](#consumer-operations)). This method blocks until a message is available. | `(Message, error)`
+`HasNext()` | Check if there is any message available to read from the current position| (bool, error)
 `Close()` | Closes the reader, disabling its ability to receive messages from the broker | `error`
 
 #### "Next" example
@@ -422,6 +439,7 @@ Parameter | Description | Default
 `MessageChannel` | The Go channel used by the reader. Messages that arrive from the Pulsar topic(s) will be passed to this channel. |
 `ReceiverQueueSize` | Sets the size of the reader's receiver queue, i.e. the number of messages that can be accumulated by the reader before the application calls `Next`. A value higher than the default of 1000 could increase reader throughput, though at the expense of more memory utilization. | 1000
 `SubscriptionRolePrefix` | The subscription role prefix. | `reader`
+`ReadCompacted` | If enabled, the reader will read messages from the compacted topic rather than reading the full message backlog of the topic. This means that, if the topic has been compacted, the reader will only see the latest value for each key in the topic, up until the point in the topic message backlog that has been compacted. Beyond that point, the messages will be sent as normal.|
 
 ## Messages
 
@@ -448,10 +466,12 @@ The following methods parameters are available for `ProducerMessage` objects:
 Parameter | Description
 :---------|:-----------
 `Payload` | The actual data payload of the message
+`Value` | Value and payload is mutually exclusive, `Value interface{}` for schema message.
 `Key` | The optional key associated with the message (particularly useful for things like topic compaction)
 `Properties` | A key-value map (both keys and values must be strings) for any application-specific metadata attached to the message
 `EventTime` | The timestamp associated with the message
 `ReplicationClusters` | The clusters to which this message will be replicated. Pulsar brokers handle message replication automatically; you should only change this setting if you want to override the broker default.
+`SequenceID` | Set the sequence id to assign to the current message
 
 ## TLS encryption and authentication