[distribution] remove pulsar-io-debezium nar package (apache#3656)

*Motivation*

Fixes apache#3651

`pulsar-io-debezium` is a normal module but not a connector package.
it was added as a connector package by mistake at apache#3601. This would
cause failing to load connectors during broker starts up.

*Changes*

- remove nar plugin from `pulsar-io-debezium`
- remove `pulsar-io-debezium` from distribution
- add `pulsar-io-kafka-connect-adaptor` in the website

distribution/io/src/assemble/io.xml

@@ -63,7 +63,6 @@
     <file><source>${basedir}/../../pulsar-io/data-generator/target/pulsar-io-data-generator-${project.version}.nar</source></file>
     <file><source>${basedir}/../../pulsar-io/canal/target/pulsar-io-canal-${project.version}.nar</source></file>
     <file><source>${basedir}/../../pulsar-io/netty/target/pulsar-io-netty-${project.version}.nar</source></file>
-    <file><source>${basedir}/../../pulsar-io/debezium/target/pulsar-io-debezium-${project.version}.nar</source></file>
     <file><source>${basedir}/../../pulsar-io/mongo/target/pulsar-io-mongo-${project.version}.nar</source></file>
   </files>
 </assembly>

pulsar-io/debezium/pom.xml

@@ -101,14 +101,4 @@
 
   </dependencies>
 
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.nifi</groupId>
-        <artifactId>nifi-nar-maven-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-
 </project>

site2/website/data/connectors.js

@@ -53,6 +53,12 @@ module.exports = [
         type: 'Sink',
         link: null
     },
+    {
+        name: 'kafka-connect-adaptor',
+        longName: 'Apache Kafka Connect Adaptor',
+        type: 'Source, Sink',
+        link: 'http://kafka.apache.org/'
+    },
     {
         name: 'kafka',
         longName: 'Apache Kafka',