title: Try to run "npm start" after creating office add-in project
body: <p>I created a office365 add-in project in apline container following the online instructions.
  However, when I try to run "npm start". it gives following error:</p>
  
  <p><strong>Starting the dev server... (webpack-dev-server --mode development)
  (node:191) UnhandledPromiseRejectionWarning: Error: Platform not supported: linux</strong></p>
  
  <p>So does that mean, I can only run the add-in project on Windows?</p>