Update README.md

Author: mynameiskenlee

README.md

@@ -4,12 +4,12 @@ starter template for building menubar app in flutter
 
 <img src="https://github.com/mynameiskenlee/flutter_macos_menubar_example/blob/master/Demo.png?raw=true" width="250" />
 
-Use [multi_windows](https://github.com/mynameiskenlee/flutter_macos_menubar_example/tree/multi_windows) branch for example with addtional windows
+Use [multi_windows](https://github.com/mynameiskenlee/flutter_macos_menubar_example/tree/multi_windows) branch for example with addtional windows (select include all branches when using this template)
 
 ![multi_windows demo](multi_window.gif)
 
 -------------------------------------------------------
-## Getting Started
+## Getting Started (for single window menu bar app only)
 use this template or follow the following step in your flutter project:
 
 1. Change to Content of macos/Runner/AppDelegate.swift