Thank you so much!
Yeah the Rasa Docs are awesome except that they don’t document this kind of stuff.
This is exactly why I want to split the domain. One file per key. Maybe later also split the responses into multiple files.
I will try some stuff and research myself, and post a question about it if I don’t find anything. I already have a similar question about the Action Server anyway.
If I find a solution I’ll post it here in this reply 
Edit: I asked a question.
Edit: Nobody replied. So I decided to go back to a single domain file, but left the folder there just in case (so the folder was there on GitHub too). I deployed the chatbot on the server, and went to Rasa X’s “Domain” tab, only to see that it automatically detected all the domain files in the folder as well as the original one. So that’s solved