Add Python language reference docs (#30686)
Summary:
This exposes our audit of https://docs.python.org/3/reference/ with descriptions for each line item.
To generate the `.rst` from the Quip:
```bash
pip install m2r
m2r jit_language_reference.md
```
https://driazati.github.io/pytorch_doc_previews/30686/jit.html#python-functions-and-modules
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30686
Pulled By: driazati
Differential Revision: D19219587
fbshipit-source-id: 249db9b5ee20e38804d4302bbfeca7d54f27d0bd
