title: Add item with icon to a menu in Google Apps Script
body: <p>Is it possible to add a menu item with an icon (like the icons of undo/redo button) to a custom menu item?</p>
  
  <p>The <a href="https://developers.google.com/apps-script/reference/base/menu#addItem(String,String)" rel="noreferrer">documentation of the Class Menu</a> doesn't mention it, so I guess it's not possible, but maybe there's a way to achieve this?</p>
  
  <p>Thanks!</p>