更新readme

Author: xljiulang

WebApiClientCore.Extensions.JsonRpc/README.md

@@ -9,6 +9,16 @@ WebApiClientCore的JsonRpc调用扩展
 public interface IUserApi 
 {
     [JsonRpcMethod("add")]
-    ITask<JsonRpcResult<User>> AddAsync([JsonRpcParam] string name, [JsonRpcParam] int age);
+    ITask<JsonRpcResult<User>> AddAsync([JsonRpcParam] string name, [JsonRpcParam] int age, CancellationToken token = default);
 }
+```
+
+```
+POST /jsonrpc HTTP/1.1
+Host: localhost:5000
+User-Agent: WebApiClientCore/1.0.6.0
+Accept: application/json; q=0.01, application/xml; q=0.01
+Content-Type: application/json-rpc
+
+{"jsonrpc":"2.0","method":"add","params":["laojiu",18],"id":1}
 ```