参考 Make a README Because no one can read your mind (yet)
Reamdme支持多种文件格式，最常见的是Markdown。
Readme学习可以参考reference guide
Readme 格式练习可以参考 interactive tutorial
While READMEs can be written in any text file format, the most common one that is used nowadays is Markdown. It allows you to add some lightweight formatting. You can learn more about it here, which also has a helpful reference guide and an interactive tutorial. Some other formats that you might see are plain text, reStructuredText (common in Python projects), and Textile).
**粗体** _斜体_ [链接](http://example.com) `代码` - 列表 > 引用。你还可以使用@来通知其他用户。