Update README.md

Signed-off-by: Jiangnan Jia <[email protected]>

Author: jnan806

README.md

@@ -18,7 +18,7 @@ See the [中文文档](https://opensergo.io/zh-cn/) for document in Chinese.
 
 1. Add dependency in Maven `pom.xml`:
 
-```xml
+``` xml
 <!-- replace here with the latest version -->
 <dependency>
     <groupId>io.opensergo</groupId>
@@ -29,20 +29,28 @@ See the [中文文档](https://opensergo.io/zh-cn/) for document in Chinese.
 
 2. Subscribe data from OpenSergo control plane:
 
-```java
+``` java
 // 1. Create client with remote host and port of OpenSergo control plane
 OpenSergoClient client = new OpenSergoClient(host, port);
 // 2. Start the OpenSergo client.
 client.start();
 
-// 3. Subscribe the config of the target (namespace, appName, kind)
-client.subscribeConfig(new SubscribeKey("default", "my-service", configKind),
-    new OpenSergoConfigSubscriber() {
+// 3. Prepare for subscribing the config of the target (namespace, appName, kind)
+// 3.1 Create the SubscribeKey of your target
+SubscribeKey subscribeKey = new SubscribeKey("default", "my-service", configKind);
+// 3.2 Create the SubscribeInfo of your target by subscribeKey
+OpensergoClientSubscribeInfo subscribeInfo = new OpensergoClientSubscribeInfo(subscribeKey);
+// 3.3 Add a Subscriber for you target which would listen changes of target
+subscribeInfo.addSubscriber(new OpenSergoConfigSubscriber() {
         @Override
         public boolean onConfigUpdate(SubscribeKey subscribeKey, Object dataList) {
-            // Handle received config here
+            // TODO Handle received config here
             System.out.println("key: " + subscribeKey + ", data: " + dataList);
             return true;
         }
     });
+
+// 4. Register into OpenSergoClient the SubscribeInfo which was builded above.
+// And then the client will subscribe config automatic.
+client.registerSubscribeInfo(subscribeInfo);
 ```