项目已经搭建，需要添加stylus

1. cmd， 进入项目所在目录， 输入vue add style-resources-loader (或 npm i vue-cli-plugin-style-resources-loader)
2. vue.config.js中，修改.styl文件所在目录

// vue.config.js详情

const path = require('path');

module.exports = {
  pluginOptions: {
    'style-resources-loader': {
      preProcessor: 'stylus',
      patterns: [
        // path.resolve(__dirname, 'src/styles/abstracts/*.styl'),
        path.resolve(__dirname, 'src/assets/styles/index.styl'),
      ],
    }
  }