yes my native language is Czech. I can provide some translation support for you (from English to Czech). Write me instructions how to do it. But there could be disunited opinion on exact translation. You can translate one sentence with two,tree different way. With little variations. I always try to translate the way that everybody will understand the meaning. Someone may disagree with my translation. In the past I found in Egroupware sentences, witch I would translate different way. I don’t know how many people participate on ENG - CS translation and who decide which translation is the right one.That’s why I always correct and keep my own language files. Of course I used “Custom translation” in admin menu as well. But this way do not work for all translations in Egroupware.
Anyway, I would like to know the answer for my original question. If you can provide. I am quite long time user (admin) in our non-profit organisation. Which is library. And in the past I many times needed to change not only the language files. I am not quite familiar with docker. I know I can dig it on google. And I already did, and I know some basics. But it takes long time, witch I do not have. So I will appreciate If you can give me just a couple hints.