Youtube Empowered

Tweaks youtube to be more focused and powerful.

## Motivation: The 'Enhancer for Youtube' extension is very useful and powerful, which is why it is all the more tragic that it is proprietary. So, I want to implement all the features (that I think are useful) from that extension in libre code. List of features: - Videos start in theater mode by default - Videos in Theater mode take up the entire viewport - Scrolling down beyond the video playback area shows a mini player that follows you List of planned features from Enhancer: - Prevent autoplay on videos in the background List of planned features not from Enhancer: - Keyboard navigation for comments, like RES - Have a way to show only comments below a video, only the description, or only recommendations; like NewPipe List of features that will not be added: - Ad-blocker: Use uBlock Origin - Speed controls: Use Video Speed Controller - Theming: Install Stylus - Cinema Mode: Use a dark theme