docs: 在贡献指南中推荐 XamlStyler

CONTRIBUTING.md

@@ -41,7 +41,7 @@ Magpie 没有广泛的测试过，因此错误不可避免。希望你能向开
 
 贡献代码时你需要遵守一些准则：
 
-1. 和现有的代码风格保持一致，包括花括号不换行，tab 缩进，变量、类、源文件等的命名方式，所有源码文件格式均为 UTF-8 without BOM，倾向于使用行注释，git 消息风格等等。下面是一个代码风格的示例：
+1. 和现有的代码风格保持一致，包括花括号不换行，tab 缩进，变量、类、源文件等的命名方式，所有源码文件格式均为 UTF-8 without BOM，倾向于使用行注释，git 消息风格等等。格式化 XAML 文件时请安装 [XamlStyler](https://github.com/Xavalon/XamlStyler) 插件。下面是一个代码风格的示例：
     ``` c++
     // ClassName.h
     

CONTRIBUTING_EN.md

@@ -41,7 +41,7 @@ Like all other open source projects, you need to initiate pull requests to contr
 
 You need to follow the following rules when contributing code:
 
-1. Keep in the same style as that of the current code, including no change-of-line for curly brackets, using tabs for indentation, the ways to name variables, classes, and source files, using UTF-8 without BOM encoding, preferring single-line comments, and using git-style messages, etc. Here is an example:
+1. Keep in the same style as that of the current code, including no change-of-line for curly brackets, using tabs for indentation, the ways to name variables, classes, and source files, using UTF-8 without BOM encoding, preferring single-line comments, and using git-style messages, etc. Please install [XamlStyler](https://github.com/Xavalon/XamlStyler) for formatting XAML files. Here is an example:
     ``` c++
     // ClassName.h