Add an option for translations using Weblate/Crowdin

[klascal]

The Kobalt UI currently is only in English, while the native reader supports other languages.

Would it be possible to add a language picker in the Kobalt settings or automatically use the language of the system?
And can an option be added for us to translate it using Weblate, Crowdin, etc.?

Alvast bedankt, Nico!

[nicoverbruggen]

This is planned for when v1.0 is done!