Nextjs: App router support for HMSPrebuilt (#1690)

context for app router

docs/javascript/v2/quickstart/prebuilt-quickstart.mdx

@@ -79,7 +79,7 @@ export default App;
 
 <Tab id="add-component-1">
 
-For Next.js, you can add the Prebuilt component to your `pages/index.js` file:
+For Next.js, you can add the Prebuilt component to your `pages/index.js` file. If you have opted for app router during initialization, you can add the snippet in the `app/page.js` file. Depending on the initialization configuration, the files can be in typescript. The `src` directory is also optional and only affects the file paths:
 
 ```jsx title="pages/index.js"
 "use client";