Fix documentation to point to torch.overrides instead of _overrides. (#47842)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/47697
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47842
Reviewed By: smessmer
Differential Revision: D24951750
Pulled By: ezyang
fbshipit-source-id: df62ec2e52f1c561c864a50bac4abf4a55e4f8e6
