Add support for invidious (open source youtube frontend)

[Perflyst]

Invidious is an open source youtube frontend: https://github.com/omarroth/invidious/

Instead of adding youtube.com to a room, you can either add invidio.us or a selfhosted instance to your room to watch a specific video.

[rodolpheh]

I created a PR in the embed-video library to add support for Invidious, see https://github.com/alanshaw/embed-video/pull/21. If it is accepted, it should be only 2-3 lines of code to integrate Invidious.

[rodolpheh]

Unfortunately, the main instance of invidious will shut down on September first. See more information here