RFC: Instead of supporting more sources, support less?

[davatron5000]

One of the roadmap items was adding support for video vendors beyond YouTube and Vimeo...

Allow more/custom sources? (e.g. tiktok, etc)

Ignoring TikTok specifically for a bit... it was brought up on Mastodon that maybe we don't need more sources, but we could get away with less...

TODO 1. does it... need to limit to youtube and vimeo? couldn't you just allow the user to put anything in there and this just works its magic?

I like the simplicity of this. FitVids could calculate an aspect ratio for any iframe with a [height] and [width] and make it flexxy.