[code-quality] Need a Rosetta Stone re PyLint

I reported a problem with PyLint not knowing that __doc__ is indeed an attribute of a function. So I tried to go through and find out where PyLint makes that determination, between its own code and Astroid code. I'm lost. Is there a roadmap showing where to look for the determination that a particular member is present in a function? I want to develop a patch to fix my problem, I do.