docs updated

README.md

@@ -32,7 +32,7 @@ Or you may just follow this manual if not.
 pip install python-alipay-sdk --upgrade
 ```
 
-#### cert generation
+#### Cert generation
 ```bash
 # openssl
 OpenSSL> genrsa -out app_private_key.pem 2048  # the private key file
@@ -93,7 +93,7 @@ There is also an [example](https://github.com/fzlee/alipay/blob/master/tests/cer
 Given an alipay function, say `alipay.trade.page.pay`, we will defind a corresponding function `alipay.api_alipay_trade_page_pay()`
 Generally we will do such a translation:
 
-    function_name = "alipay_" + alipay_function_name.replace(".", "_")
+    function_name = "api_" + alipay_function_name.replace(".", "_")
 
 according to alipay document, some paremeters in `biz_content` are optional and some are not. 
 we defind functions in this way so that you can put those optional parameters in `kwargs`:

README.zh-hans.md

@@ -41,7 +41,8 @@ OpenSSL> exit
 ```
 
 在支付宝上下载的公钥是一个字符串，你需要在文本的首尾添加标记位 
-```(-----BEGIN PUBLIC KEY-----和-----END PUBLIC KEY-----) 
+```
+(-----BEGIN PUBLIC KEY-----和-----END PUBLIC KEY-----) 
 ```
 才能正常使用, 证书的格式你可以参考[这里](https://github.com/fzlee/alipay/blob/master/tests/certs/ali/ali_public_key.pem)
 
@@ -92,7 +93,7 @@ OpenSSL> exit
 对于一个支付宝的接口，比如`alipay.trade.page.pay`，则一般可以这么调用接口：`alipay.api_alipay_trade_page_pay()`.
 也就是说，我们做了这么一个转换:
 
-     内部函数名 =  alipay_ + 支付宝接口名.replace(".", "_")
+     内部函数名 =  api_ + 支付宝接口名.replace(".", "_")
 
 支付宝对于请求的biz_content,里面有一些参数必选，有一些可选。对于必选的参数，他们一般被明确定义在函数的参数里面。对于可选参数，他们一般被放在kwargs里面,然后被添加到biz_content里面去。比如`alipay.trade.page.pay`可以这么调用:
 ```python