[Auth] Create index.doc.ts for generating docs for all platforms (#5112)

* Add an index.doc.ts file that includes all exports for auto-generated docs

* Format

packages-exp/auth-exp/index.doc.ts

@@ -0,0 +1,25 @@
+/**
+ * @license
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Internal index that pulls in all the different platforms, for documentation
+// generation purposes only.
+
+// Core (Browser) index
+export * from './index';
+
+export { cordovaPopupRedirectResolver } from './index.cordova';
+export { reactNativeLocalPersistence } from './index.rn';

packages-exp/auth-exp/index.rn.ts

@@ -35,6 +35,12 @@ import { getReactNativePersistence } from './src/platform_react_native/persisten
 // Core functionality shared by all clients
 export * from './src';
 
+/**
+ * An implementation of {@link Persistence} of type 'LOCAL' for use in React
+ * Native environments.
+ *
+ * @public
+ */
 export const reactNativeLocalPersistence =
   getReactNativePersistence(AsyncStorage);