As a regular consumer of pg docs, I vehemently agree that they are incredibly detailed, and at the same time, daunting to navigate.
https://www.postgresqltutorial.com/about-us/
is a very helpful supplement to the official docs.
Unfortunately it's not comprehensive - for example it doesn't appear to cover pgcrypto extension.
[1] https://technicalwriting.tools/posts/playing-nicely-with-gen... (my blog)