Recommended projects to translate into Breton
OK. I was doing that because it was mentioned in the Gerrit merge request that the skin translation statistics were too low. Thanks for pointing me to the right place. At first sight I don’t see skins in that group, though, could you tell me where they are?
The most important skins are Vector (default on desktop) and MinervaNeue (default on mobile). Monobook is the old default desktop skin, but it's still used by many people, so it's also quite important. All three are under "Extensions used by Wikimedia - main". In any case, these three are almost completely translated to Breton, so you don't have to worry about them too much (there's just a tiny number of translations in them to complete).
The really important things to complete are "MediaWiki core" and "Extensions used by Wikimedia - main". The first one is around 4000 messages, which is big, but it's the main platform, so it's necessary. (I'm thinking of ways to break it up to smaller and easier to manage groups, but it will take some time.)
"Extensions used by Wikimedia - main" is huge, but it consists of many smaller pieces, so it's convenient to work on them one by one. You can also organize with your friends, so that each of you works on a separate piece.
I wrote some thoughts about it at this post: https://aharoni.wordpress.com/2020/10/23/amir-aharonis-quasi-pro-tips-for-translating-the-software-that-powers-wikipedia-2020-edition/ . Perhaps you'll find it useful.