project uses the vue cli3 scaffolding tool to build 
 as shown in the element official documentation. 
 npm install babel-plugin-component-D 
 then add the .babelrc file 
 {
 "presets": [
["es2015", {
  "modules": false
}]], 
 "plugins": [
[
  "component",
  {
    "libraryName": "element-ui",
    "styleLibraryName": "theme-chalk"
  }
]] 
} 
 the startup project found that babel-preset-es2015 was missing, so cnpm install-- save babel-preset-es2015 installed 
 and then the startup project reported an error 
 Error: Plugin/Preset files are not allowed to export objects, only functions.. In E:vue3-confignode_modulesbabel-preset-es2015libindex.js 
 novice Xiaobai asks for online solutions 
