安装全局nrm

1. 安装全局nrm(yrs)

   npm install nrm -g
   

2. 查看镜像列表

   nrm ls
   

3. 切换镜像

   nrm use yarn
   

4. 添加镜像

   nrm add yarn https://registry.yarnpkg.com/
   nrm add taobao https://registry.npm.taobao.org/
   nrm add taobao https://registry.npm.taobao.org/
   

5. 删除

   nrm del yarn
   

6. 测速

   nrm test yarn