Update docs for get_future support (#58107)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/58107
Test Plan: Imported from OSS
Reviewed By: SciPioneer
Differential Revision: D28387374
Pulled By: agolynski
fbshipit-source-id: 70052afbb0b07ba341ea55f7ec30f7d9759b7bd4
