Document ReactHostDelegate (#37562)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/37562

Add documentation for ReactHostDelegate

changelog: [internal] internal

Reviewed By: cortinico

Differential Revision: D45717674

fbshipit-source-id: e0d6d70edf4f4cf70b53807732b35f5fda917fc3

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

@@ -16,24 +16,51 @@ import com.facebook.react.common.annotations.UnstableReactNativeAPI
 import com.facebook.react.fabric.ReactNativeConfig
 import com.facebook.react.turbomodule.core.TurboModuleManagerDelegate
 
-/** TODO: add javadoc for class and methods */
+/**
+ * [ReactHostDelegate] is an interface that defines parameters required to initialize React Native.
+ * This interface works in combination with [ReactHost]
+ */
 @ThreadSafe
 @UnstableReactNativeAPI
 interface ReactHostDelegate {
+  /**
+   * Path to your app's main module on Metro. This is used when reloading JS during development. All
+   * paths are relative to the root folder the packager is serving files from. Examples:
+   * `index.android` or `subdirectory/index.android`
+   */
   val jSMainModulePath: String
 
+  /**
+   * Object that holds a native C++ references that allow host applications to install C++ objects
+   * into jsi::Runtime during the initialization of React Native
+   */
   val bindingsInstaller: BindingsInstaller?
 
+  /** list of [ReactPackage] to expose Native Modules and View Components to JS */
   val reactPackages: List<ReactPackage>
 
+  /** Object that holds a native reference to the javascript engine */
   val jSEngineInstance: JSEngineInstance
 
+  /**
+   * Bundle loader to use when setting up JS environment. <p>Example:
+   * [JSBundleLoader.createFileLoader(application, bundleFile)]
+   */
   val jSBundleLoader: JSBundleLoader
 
+  /** TODO: combine getTurboModuleManagerDelegate inside [ReactPackage] */
   fun getTurboModuleManagerDelegate(context: ReactApplicationContext): TurboModuleManagerDelegate
 
+  /**
+   * Callback that can be used by React Native host applications to react to exceptions thrown by
+   * the internals of React Native.
+   */
   fun handleInstanceException(error: Exception)
 
+  /**
+   * ReactNative Configuration that allows to customize the behavior of key/value pairs used by the
+   * framework to enable/disable experimental capabilities
+   */
   fun getReactNativeConfig(context: ReactContext): ReactNativeConfig
 
   @UnstableReactNativeAPI