开始使用Git来进行版本控制，常用命令如下：
git init
creates a new Git repository
git status
inspects the contents of the working directory and staging area
git add（filename）
adds files from the working directory to the staging area
git diff ( ID1 ID2 )
shows the difference between the working directory and the staging area
git commit (-m "message")
permanently stores file changes from the staging area in the repository
git log
shows a list of all previous commits
