minor fixes

README-ZH.md

 
 首先，请打开或创建Unity项目并使用Unity编辑器打开它。
 
-然后打开Project Settings，转到Player部分并**将“UIWidgets_DEBUG”添加到Scripting Define Symbols字段中。**
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-这样就启动了UIWidgets的调试模式。 在之后发布版本的时候清空这个字段。
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 #### 二、 场景构建
 
 UIWidgets应用通常构建在Unity UI Canvas上。 请按照以下步骤在Unity中创建一个

README.md

 
 #### Runtime Environment
 
-Currently UIWidgets only support MacOS(Metal), iOS(Metal), Android(Armv7, OpenGLes) and Windows(Direct3D11). More devices will be supported in the future.
+Currently UIWidgets only supports MacOS(Metal), iOS(Metal), Android(Armv7, OpenGLes) and Windows(Direct3D11). More devices will be supported in the future.
 
 ## Getting Start
 
 
 First of all, please open or create a Unity Project and open it with Unity Editor.
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-And then open Project Settings, go to Player section and **add "UIWidgets_DEBUG" to the Scripting Define Symbols field.**
-This enables the debug mode of UIWidgets for your development. Remove this for your release build afterwards.
 
 #### ii. Scene Build
 A UIWidgets App is usually built upon a Unity UI Canvas. Please follow the steps to create a