Hello Aaron, care to have a chat/call on this? I am currently looking at how we at Discourse can improve this, so any feedback you can offer is super welcome!
EDIT
And to speak to your question, each setting is documented within the setting itself, so you find text/notes/tooltips underneath the setting themselves explaining them, and each text in the description and the setting text itself is searchable, as we try to use descriptive keywords.
So while there isn’t a documentation as you may have asked for, the description helps me and I use the Filter box to search through the settings to make sense of it.
The filter box:
Searching through the tooltips to see if anything matches or deals with document… ation?
I hope this helps in a way of some sorts.