split nn.functional (#55038)
Summary:
Related to https://github.com/pytorch/pytorch/issues/52256
Splits torch.nn.functional into a table-of-contents page and many sub-pages, one for each function
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55038
Reviewed By: gchanan
Differential Revision: D27502677
Pulled By: zou3519
fbshipit-source-id: 38e450a0fee41c901eb56f94aee8a32f4eefc807
