Add jellyseer

[ibizaman]

https://docs.jellyseerr.dev

Now that https://github.com/streamyfin/streamyfin integrates with jellyseer, it's worth adding jellyseer to the supported services.

[fallenbagel]

Hey!

I'm the jellyseerr dev and I use nix.
If you'd like some help with this I'd love to spend some time discussing this on discord when I'm free :)

[ibizaman]

@fallenbagel that would be awesome. I just joined jellyseerr’s discord.

[Danguilhen]

Hey, it seems Jellyseerr and Overseerr teams are merging and created Seerr, it was announced last week:
https://docs.seerr.dev/blog/seerr-release

Might be worth to add Seerr rather than Jellyseerr when it will be added as a service upstream!?
Here is the PR for renaming jellyseerr to seerr in nixpkgs that fallenbagel is working on: NixOS/nixpkgs#450093

At the moment the OIDC support is in a drafted PR and seems to be actively progressing: seerr-team/seerr#1505