I’ve got a bunch of notes in Trilium.

I have a note for each service with the docker compose file, notes on backups, any weirdness with the setup, and when I update each service.

I also have a note for the initial setup of my server (mostly setting up docker, setting up mergerfs and snapraid).

Other than that, I have one note for each device for my setup. (Wifi AP, OPNsense router, switch, etc) That I populate with random crap I might need to know later.