Fix fx docs (#72108)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/72108
Test Plan: Imported from OSS
Reviewed By: jamesr66a
Differential Revision: D33916855
Pulled By: mrshenli
fbshipit-source-id: 5fff6c87555109e43954eff99164e68a56ff95da
(cherry picked from commit 1611c4c75c6398cdd72fb9edfd04e8f9ff2f9ece)
