yt-dlp support

Hey,

I've setup outline and really like it. Something I'd like though would be the ability to instead of embedding a YouTube video, download it automatically and store it locally.

Why? Well I want my note taking app to not be subject to the whims of a 3rd party service, and if I've linked a video, it's probably because it had useful information in it, which I wouldn't want to lose.

I assume this could be done via the api in theory? Check for YouTube urls, if there is one, grab the video then upload it to outline then replace the url in the doc with a link to the uploaded doc? I might give it a go at some point.

Thanks!