arc42 [1], rendered into whatever format you prefer for reading.
In our case we write asciidoc (sometimes markdown) and render it to HTML for each of the releases, so that a version of the documentation is delivered with the release.
The authors of arc42 also encourage users to set documentation under version control to ensure one can keep the project and its documentation in sync [2].
I am not sure what level of abstraction and automation you are aiming for but there is a pretty neat project for setting up a kubernetes cluster including automatic updates in hetzner [1]. Even if it exceeds your requirements you can scrape it to answer many of your questions.
[1] https://arc42.org/overview [2] https://faq.arc42.org/questions/G-1/