About 2 years ago I came to the conclusion that my personal documentation for tech stuff is non existent. Some excel sheet here, a saved TXT in c:\temp over there, the occasional "I still need tot rewrite and save this unsaved file in Notepad++" combined with a bunch of google keep notes.

I ended up installing Wordpress with https://basepresskb.com/docs/knowledge-base/basepress/
I use it for virtually everything. From documenting the build of a server to simply logging expensive household equipment with extended warranty.