Comment 13 for bug 992420

I've made some progress on improving translations for add-ins, starting with the night vision effect as a test:
https://github.com/PintaProject/NightVisionEffect/commit/a555c65ae35908a8206c33deeea539abad3d2d0b

And it can be translated on Pinta's Weblate instance now: https://hosted.weblate.org/projects/pinta/nightvisioneffect/

The main blocker I've hit is that the addin metadata (the label "Night Vision Effect", and the description "A simple add-in that will ...") can't be localized in the normal way, and instead need translations to be embedded in the add-in manifest (which weblate doesn't understand). It might require an extra build step to generate a new manifest with all the strings bundled together