docs: update doc for section 'Launch App From H5'

doc/LAUNCH_APP_FROM_H5.md

+## WeChat reference document
+
+- [WeChat open label jumps to APP: <wx-open-launch-app>](https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/Wechat_Open_Tag.html#%E8%B7%B3%E8%BD%ACAPP%EF%BC%9Awx-open-launch-app)
+- [App gets the extinfo data in the open tag <wx-open-launch-app>](https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/APP_GET_EXTINF.html)
+
+## Platform differences
+
+- The event type of **Launch-App-From-H5** on Android is `WeChatShowMessageFromWXRequest`
+- The event type of **Launch-App-From-H5** on IOS is `WeChatLaunchFromWXRequest`
+
+> ### iOS specific configuration
 
-## IOS
 Please register your WXApi in your `AppDelegate`:
+
 ```oc
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     //向微信注册
@@ -9,4 +20,30 @@ Please register your WXApi in your `AppDelegate`:
 }
 ```
 
-> If you want to get ext from website, please call ``fluwx.getExtMsg()`。`For details, please read the example.
+## Example
\ No newline at end of file
+
+```dart
+void handle_launch_from_h5() {
+  Fluwx fluwx = Fluwx();
+
+  fluwx.addSubscriber((response) {
+    // 1. Handle responses separately for android and ios
+    if (response is WeChatShowMessageFromWXRequest) {
+      debugPrint("launch-app-from-h5 on android");
+      // do something here only for android after launch from wechat
+    } else if (response is WeChatLaunchFromWXRequest) {
+      debugPrint("launch-app-from-h5 on ios");
+      // do something here only for android after launch from wechat
+    }
+
+    // 2. Or handling responses together for android and ios
+    if (response is WeChatLaunchFromWXRequest ||
+        response is WeChatShowMessageFromWXRequest) {
+      debugPrint("launch-app-from-h5");
+      // do something here for both android and ios after launch from wechat
+    }
+  });
+}
+```
+
+> If you want to get ext from website, please call `fluwx.getExtMsg()`。For details, please read the example project.

doc/LAUNCH_APP_FROM_H5_CN.md

+## 微信参考文档
+
+- [微信开放标签 <wx-open-launch-app> 跳转App](https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/Wechat_Open_Tag.html#%E8%B7%B3%E8%BD%ACAPP%EF%BC%9Awx-open-launch-app)
+- [App获取开放标签 <wx-open-launch-app> 中的 extinfo 数据](https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/APP_GET_EXTINF.html)
+
+## 平台差异
+
+- 安卓端 **微信唤起App** 的事件类型为 `WeChatShowMessageFromWXRequest`
+- IOS端 **微信唤起App** 的事件类型为 `WeChatLaunchFromWXRequest`
+
+> ### iOS 特定配置
 
-## IOS
 请在你的`AppDelegate`中主动注册`WXApi`
+
 ```oc
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     //向微信注册
@@ -9,5 +20,30 @@
 }
 ```
 
-> 如你想主动获取从网页传进来的值 ，请主动调用`fluwx.getExtMsg()`。更多信息请参考example.
+## 示例
+
+```dart
+void handle_launch_from_h5() {
+  Fluwx fluwx = Fluwx();
+
+  fluwx.addSubscriber((response) {
+    // 1. 为安卓和ios分开处理响应
+    if (response is WeChatShowMessageFromWXRequest) {
+      debugPrint("launch-app-from-h5 on android");
+      // 从微信启动后，在这里只为 android 做一些事情
+    } else if (response is WeChatLaunchFromWXRequest) {
+      debugPrint("launch-app-from-h5 on ios");
+      // 从微信启动后，在这里只为 ios 做一些事情
+    }
+
+    // 2. 或者为安卓和ios一起处理响应
+    if (response is WeChatLaunchFromWXRequest ||
+        response is WeChatShowMessageFromWXRequest) {
+      debugPrint("launch-app-from-h5");
+      // 从微信启动后，在这里为 android 和 ios 做一些事情
+    }
+  });
+}
+```
 
+> 如你想主动获取从网页传进来的值 ，请主动调用`fluwx.getExtMsg()`。更多信息请参考example项目.