Document change for DDP enabled on Windows platform (#45392)
Summary:
Document change for DDP enabled on Windows platform
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45392
Reviewed By: gchanan
Differential Revision: D23962344
Pulled By: mrshenli
fbshipit-source-id: 8924c6ca36d68699871d8add3e0aab6542ea269c
