Mobile YouTube Fix von ris58h

Shortcuts:
Spacebar - Play/Pause.
k - Play/Pause.
m - Mute/unmute the video.
Left/Right arrow - Seek backward/forward 5 seconds.
j - Seek backward 10 seconds in player.
l - Seek forward 10 seconds in player.
< - Slow down the video playback rate.
> - Speed up the video playback rate.
1 to 9 - Seek to the 10% to 90% of the video.
0 - Seek to the beginning of the video.