fixed the first line of torch.rst to match the __init__.py file's first line (#49584)
Summary:
Changed the first line of the torch.rst file to match that of the __init__.py file
Fixes https://github.com/pytorch/pytorch/issues/49228
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49584
Reviewed By: VitalyFedyunin
Differential Revision: D25639260
Pulled By: mrshenli
fbshipit-source-id: a0bafd945ff92115eed932662feedc46d29dfaab
