Introduce the torchrun entrypoint (#64049)
Summary:
This PR introduces a new `torchrun` entrypoint that simply "points" to `python -m torch.distributed.run`. It is shorter and less error-prone to type and gives a nicer syntax than a rather cryptic `python -m ...` command line. Along with the new entrypoint the documentation is also updated and places where `torch.distributed.run` are mentioned are replaced with `torchrun`.
cc pietern mrshenli pritamdamania87 zhaojuanmao satgera rohan-varma gqchen aazzolini osalpekar jiayisuse agolynski SciPioneer H-Huang mrzzd cbalioglu gcramer23
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64049
Reviewed By: cbalioglu
Differential Revision: D30584041
Pulled By: kiukchung
fbshipit-source-id: d99db3b5d12e7bf9676bab70e680d4b88031ae2d
