补充getMediaPlayerList接口注释及postman示例

server/WebApi.cpp

@@ -741,6 +741,8 @@ void installWebApi() {
         val["online"] = (bool) (MediaSource::find(allArgs["schema"],allArgs["vhost"],allArgs["app"],allArgs["stream"]));
     });
 
+    //获取媒体流播放器列表
+    //测试url http://127.0.0.1/index/api/getMediaPlayerList?schema=rtsp&vhost=__defaultVhost__&app=live&stream=obs
     api_regist("/index/api/getMediaPlayerList",[](API_ARGS_MAP_ASYNC){
         CHECK_SECRET();
         CHECK_ARGS("schema", "vhost", "app", "stream");