DOC Adds register_module_full_backward_hook into docs (#58954)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/54443
Adds `register_module_full_backward_hook` into the index so it is rendered in the html docs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58954
Reviewed By: ngimel
Differential Revision: D28801816
Pulled By: jbschlosser
fbshipit-source-id: a2e737fe983e5d7e4e26d7639183bca34b571cb8
