安装yarn

​​https://yarnpkg.com/lang/zh-hans/docs/install/​​

使用国内镜像加速npm和yarn

1. npm config set registry=https://registry.npm.taobao.org
2. yarn config set registry https://registry.npm.taobao.org
3. 下载cnpm：npm install -g cnpm --registry=https://registry.npm.taobao.org