[FX] Edits after comprehensive pass over docs (#51705)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51705
Pull Request resolved: #51679
Test Plan: Imported from OSS
Reviewed By: Chillee
Differential Revision: D26246231
Pulled By: jamesr66a
fbshipit-source-id: 8d6278a9fe1da5e6c34eff4fedc4c7e18533fe0f
