title: Change default Open-File operation for certain extensions
body: <p>Is there a way to change the default behaviour on double-click (Left-Click) only for certain file extensions? 
  For example I want <code>.pdf</code> Files to open with the dafault application automatically. As of now I have to open context menu and select <code>Open\Run</code> via <code>SideBarEnhacement</code> package. </p>