Move off hardcoded plural forms

[turtlegarden]

Is your feature request related to a problem? Please describe.

When I was translating the app, I found that there were various strings with hardcoded singular and plural forms. This can be problematic for languages with e.g. a dual form (for 2 games) and a plural form (3 or more) as well as the singular

Describe the solution you'd like

Usage of ngettext may be a good way to resolve this problem.

Additional context

It might also be nice to add a translator-credits in the About window :) If wanted I can work on these changes and submit a pull request with updated PO files, but I think merging translations from Weblate first would be best.

[kra-mo]

Yeah, this makes sense. Translation credit is already there, libadwaita shows it conditionally based on the language someone is using the app in ^^

I would appreciate a pull request for ngettext, thank you :)

[kra-mo]

And I merged Weblate

[turtlegarden]

Awesome, I'll work on that!