Make an Option for Serializing videos (Adding an incrementing number before each video starting from 1 for example) when downloading a Playlist.

Make an Option for Serializing videos (Adding an incrementing number before each video starting from 1 for example) when downloading a Playlist, It should be a minor thing to code, but A LIFESAVER, especially when downloading over 30/50 or even more videos sometimes. In many places for ex. even in you tube most videos in playlist aren't serialized. SO this would really be helpful.
Hopefully you guys will see it through.