Weblate: Set up format check

[manuroe]

Weblate offers some string format checks.

Detecting errors when the translator is adding their contributions instead of at the release time would be a huge DevX improvement!

[bmarty]

I have just added the "Placeholders" check, let's see if something happen:

[bmarty]

"Java Format" seems to be the correct check.

[manuroe]

Does it check if the format is the same in the translation and the original string? What happens if the translator add or remove some formatting?