Repo cleanup

So, while doing #317 I noticed that there probably are some folder we can remove. I don't know if we should wait till we get some type of [tests implemented](https://github.com/JupiterBroadcasting/jupiterbroadcasting.com/issues/286#issuecomment-1215477732) though before we start removing a bunch of stuff from the site... :thinking:

So far this is what I think could probably be removed (didn't try it but don't know what it's used for):

- `themes/sub`
- `themes/jb/assets/css/libs/twitch.sass`
- `themes/jb/assets/css/libs/videojs.css`
- `.github/workflows/main.yml`
- this one I think we can remove because @StefanS-O already setup the redirector for the new domain (new.jb.com), and so I don't actually know what this is doing... :thinking:
- This will need to be done after the merging of #317 to ensure it doesn't mess up deployments to the jb-live.jb.net
- whoever ends up owning that domain I can work with to implement [this](https://github.com/JupiterBroadcasting/jupiterbroadcasting.com/issues/284#issuecomment-1215096665), so they don't have to keep running a server to handle redirects