I have a growing .nb file of constants and function definitions that automatically saves to a package file. My project is getting large enough that I need to start documenting function calls etc. for my own use! Where is this sort of thing documented?
Thank you 
Hi Richard,
Not sure what you mean by “hover help”, can you provide more details? For generating documentation similar to WL documentation take a look at this.
At the recent Wolfram Technology Conference, in SW’s keynote he mentioned that support for generating documentation is on the roadmap. Don’t remember if it was for 12.2 or later.
Thank you, by “hover help” I was referring to the widget that pops up in Mathematica when you hover with the mouse over a built-in name.