使用 git worktree 建立多個工作區

Reference: 

https://medium.com/@kmsh3ng/%E4%BD%BF%E7%94%A8-git-worktree-%E5%BB%BA%E7%AB%8B%E5%A4%9A%E5%80%8B%E5%B7%A5%E4%BD%9C%E5%8D%80-5a02f6d9d3fd