Add entry for subsonic plugin for upmpdcli

[GioF71]

As requested in the discussion. Please let me know if I need to reduce the amount of information or if I need to arrange it differently

[deluan]

Thanks for the PR, but can you make the entry short, like the others? I may change this section in the future to allow more info about the clients, but for now it is a simple list. Something like this would be better:

• upmpdcli - expose Navidrome as a UPnP/DLNA media library

[GioF71]

Corrected as per your request

[GioF71]

I was thinking if we can maybe link the discussion? We can stay in one line. The 'problem' with the documentation of upmpdcli is that the subsonic plugin is just a plugin, and there is only a small mention to Navidrome. I would keep the discussion updated with the changes if this is something that can be useful. Thanks

[deluan]

Yeah, linking to the discussion is fine.

[GioF71]

Thank you I just updated the branch.