warning: LF will be replaced by CRLF in README.md. The file will have its original line endings in your working directory.
解决方法:先运行 git config core.autocrlf true 然后在使用 git add .
git config core.autocrlf true
git add .
https://git-scm.com/book/zh/v1/自定义-Git-配置-Git
Git core.autocrlf 配置说明