[DDP Comm Hook] Add debugging communication hooks to ddp_comm_hooks.rst (#64352)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64352
as title
ghstack-source-id: 137246253
Test Plan: N/A
Reviewed By: rohan-varma
Differential Revision: D30694089
fbshipit-source-id: a78110b11d59bb0718f43c99ede23f2fd8ab21d0
