Add docs entry for `adjoint`. (#68869)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68869
As per title.
cc brianjo mruberry anjali411
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D32647456
Pulled By: anjali411
fbshipit-source-id: 2cb053a6884e2b22d3decc058e86d10f355fcb84
