For all this, please post an issue at https://framagit.org/luc/lufi/issues. If you don't have a framagit.org account, you can register for free, and even use your github account to do it.
All issues opened on github will be asked to move here.
git remote add upstream https://framagit.org/luc/lufi
git fetch upstream
git checkout -b my-patch upstream/development
git push -u origin my-patch:mypatch
Lufi comes with seven languages.
If you want to add more languages, please help on https://weblate.framasoft.org/projects/lufi/development/.
There are just a few sentences, so it will be quick to translate.
If you add sentences to translate, just do make locales to update the pot file.
Please read the wiki page about creating new theme and do a merge request to include your theme in the official repository.
You can make a donation to the author on Tipeee or on Liberapay.
You can now go back to wiki's homepage.