add docs

Author: coado

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactHost.kt

@@ -189,6 +189,13 @@ public interface ReactHost {
 
   /** Remove a listener previously added with [addReactInstanceEventListener]. */
   public fun removeReactInstanceEventListener(listener: ReactInstanceEventListener)
-
+  
+  /** 
+   * Sets the source of the bundle to be loaded from the packager server and updates the packager connection.
+   *
+   * @param debugServerHost host and port of the server, for example "localhost:8081"
+   * @param moduleName the module name to load, for example "js/RNTesterApp.android"
+   * @param queryBuilder a function that takes current packager options and returns updated options
+   */
   public fun setBundleSource(debugServerHost: String, moduleName: String, queryBuilder: (Map<String, String>) -> Map<String, String> = { it })
 }