title: Cannot find module 'umi'
body: <p>I just start to learn umijs so, when I try to start (npm start ) then it saw error (Cannot find module 'umi')</p>
  <blockquote>
  <p>Cannot find module 'umi'
  Require stack:</p>
  </blockquote>
  <ul>
  <li>E:\Umijs\myapp.umirc.ts</li>
  </ul>