I have started reading the https://github.com/mawww/kakoune page.
It contains “See :doc keys goto-commands” links.
But does not mention how to return from the doc page. (How to exit the help. How to quit the doc.)
After a day, I have a guess that maybe “doc” opens a (debug) buffer, and what one wants is to close (“delete”) this buffer (with “:db”). Or, alternatively, switch to other buffer (with “:bn”, “:bp” or something).
Are these the proper commands? (Or are there simpler (1-keystroke) which I missed?)