npm WARN deprecated core-js@2.6.11: core-js@<3

Administrator@GuoXinYu MINGW64 /d
$ npm install -g vuepress
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not 
recommended for usage due to the number of issues. Please, upgrade your dependencies to
 the actual version of core-js@3.
D:\nodejs\npm-global\vuepress -> D:\nodejs\npm-global\node_modules\vuepress\cli.js


npm install --save  -g core-js@^3

安装 vue/cli
npm install -g @vue/cli

运行脚手架
vue ui