I would like to offer translation of GUI for Croatian language - where to submit proposition and offer for contribution?
Thnx 
Welcome!
Thanks a lot for the offer, much appreciated. I currently have two ways translators do their work:
- web-based via the Transifex service where you’d register an account (it’s free), apply to join the project as a translator, I’ll approve it and then you can translate in their web interface
- file-based where you’d download updated translation files from my source code repository, edit the files with a specialized program such as POEdit (free) & send me the updated files via email
Both ways are perfectly fine for me. Let me know what you’d prefer.
I’ve also written up some advice for translators here you should give a look. The section isn’t that long.