Add GradBucket::parameters() to ddp_comm_hooks.rst (#62877)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62877
as title
ghstack-source-id: 135214612
Test Plan: N/A
Reviewed By: rohan-varma
Differential Revision: D30153490
fbshipit-source-id: d4cec434a53ef6e65b60c065804884d1a114aa0d
