(Feature request) Lyrics translation with DeepL free API

[Zerodya]

DeepL has a free plan up to 500,000 characters per month. Could it be possible to integrate its API in the lyrics plugin?

Looking at the documentation, only the Azure Translator resource is currently supported, but by looking it up I saw that it is a pay as you go service with a free trial, so DeepL could be a better choice. What do you think?

[snejus]

I don't see why not, that's a good idea!

[Zerodya]

Cool! In the meantime, (A)I made a quick script to translate the lyrics in my library using the DeepL API, which I put into this gist: https://gist.github.com/Zerodya/301ade170c94861268b9bffef385b096

Just sharing in case it's useful to someone else too, or maybe it could even speed up the API implementation in Beets.

I admit I haven't looked into making a PR to beets yet, and while I could, I think it's better for someone else with more experience in Beets code to do it, since I also lack the motivation now that I can translate the lyrics anyway.