Where are the .rst files that are needed for generation located?

[asoftbird]

The bpystubgen helptext mentions this:

input Source directory where *.rst files are located

Where do I get these .rst files? Is it the rst files in the manual source code? Is it something located in a blender build directory? (and if so, where?)

It's entirely unclear where the files are located, so a bit more guidance here would be nice.

I currently don't know where to start, since I need a functional version for blender 3.5.0 which doesn't yet exist as a blender-stub version.