Hints for privacybrowser in main

Warnings

• screenshot-download-error
  Error while downloading screenshot from 'https://gitweb.stoutner.com/?p=PrivacyBrowserPC.git;a=blob_plain;f=doc/privacybrowser-window.png;hb=HEAD': Failed to download file: Connection timed out after 60002 milliseconds
  This might be a temporary server issue, or the screenshot is no longer available.