Doc warnings (#41068)
Summary:
solves most of gh-38011 in the framework of solving gh-32703.
These should only be formatting fixes, I did not try to fix grammer and syntax.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41068
Differential Revision: D22411919
Pulled By: zou3519
fbshipit-source-id: 25780316b6da2cfb4028ea8a6f649bb18b746440
