[Easy][FSDP] (Reland) Doc fixes (#74834)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74834
Reland of https://github.com/pytorch/pytorch/pull/74214.
Includes fixing https://github.com/pytorch/pytorch/issues/74694.
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D35188146
Pulled By: awgu
fbshipit-source-id: fbb1a2f22a2121f39cdb2fae3519a9d135b298f7
(cherry picked from commit 710beed13121631dac45e96834f4c0c9cf1678b1)
