docments (and perhaps other) parsers

Prework

• Read and abide by the Great Docs code of conduct and contributing guidelines.
• Search for duplicates among the existing issues (both open and closed).

Proposal

Describe the new feature clearly and concisely. If applicable, write a minimal example in Python or in pseudo-code to show input, usage, and desired output.

It is inevitable that Python documentation guidelines may shift or evolve, and there are already competing documentation standards. One that I particularly enjoyed was fastai's docments, which intervweaves comments and parameters on a line-by-line basis:

def add(
    a:int, # the 1st number to add
    b=0,   # the 2nd number to add
)->int:    # the result of adding `a` to `b`
    "The sum of two numbers."
    return a+b

Their parser is out there and I'm willing to take a stab at it, though I am not nearly as good a Python programmer as I would likely need to be. Just putting this on your radar, and thanks as always for the awesome work!