I’m not an organisation, just an individual who likes to use that sort of board to organise himself.
Is anyone using something they’d recommend? Preferably ready to go with Docker of course.
Yes, it does offer importing from Trello: In a “project” (i.e. a collection of boards), after clicking the plus-button to add a new board, you can either just give it a name and create an empty board, or your can click “import from Trello”. I haven’t tried it, though, I’m not a Trello user (because why should I; I have Planka, haha). You can probably try out the import capability with their demo instance.
Have fun with your self-hosting adventures!