Faster Youtube Playback Speed par Preyum Kumar

Usage
The `shift + >` will increase the speed to beyond 2x at steps of 0.25x but the `shift + <` will bring the speed directly to 1.75x.

Desclaimer
The extension is a fork of Faster-Playback-On-Youtube. The original extension was made by Pierre Fenoll. I have made some changes to the original extension to make it work a bit cleaner but I am currently unable to add other keys as a way to change the playback speed, if that is done it will make the extension more usefull and the speed can be reduced in steps just the way it can be increased.