Is there a way we can have it so this module supports Youtube thumbnail URLs? Here is a relevant [Stackoverflow question](http://stackoverflow.com/questions/2068344/how-do-i-get-a-youtube-video-thumbnail-from-the-youtube-api). Ideally the regex would support URLs such as ``` https://img.youtube.com/vi/<insert-youtube-video-id-here>/default.jpg https://img.youtube.com/vi/<insert-youtube-video-id-here>/hqdefault.jpg ``` Along with the other quality thumbnails.