[hackathon][DataPipe] adding .pyi file generation for torch.utils.data.datapipes (#67374)
Summary:
Stack from [ghstack](https://github.com/ezyang/ghstack):
* __->__ https://github.com/pytorch/pytorch/issues/67374
This is a work in progress.
Related TorchData issue: https://github.com/pytorch/data/issues/80
cc VitalyFedyunin ejguan NivekT
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67374
Reviewed By: H-Huang
Differential Revision: D32153211
Pulled By: NivekT
fbshipit-source-id: b4c61f191f20fd98ca44bb9e4f972c6d812994a0
