Fixed links to RNN docs in comments (#68828)
Summary:
Fixed links to RNN docs in comments
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68828
Reviewed By: soulitzer
Differential Revision: D32702384
Pulled By: jbschlosser
fbshipit-source-id: 577c88842cde555534d9a39fa7dfd24164d71552
