title: Add service worker code completion to JetBrains WebStorm
body: <p>I am using WebStorm.</p>
  
  <p>How can I add code completion for JavaScript Service Workers?</p>
  
  <p>I assume I need to add the type-script file in <code>settings/languages&amp;frameworks/javascript/libraries/</code> however I do not see it in the list.</p>