A very lofi solution I have been using is tbls [1]. It is a native cli utility that generates documentation from db schema (and includes comments in the db as well).
It can output in markdown with embedded svg diagrams (which is great for previewing in github) as well as yaml (which I use for generating models).
It is not quite polished but works pretty well. Also all the db diagrams and docs are committed alongside code in the repo which is a big plus for me.