title: Integrate an option to explorer context menu with Electron
body: <p>I'm building an app which should be integrated through an option in the context menu of Windows explorer and Mac finder.  I couldn't find a relevant option in Electron's documentation.</p>
  
  <p>For example, when I right-click a file in Windows explorer / Mac finder, I want this option from my Electron app to appear in that menu.  Is it possible?</p>