update windows build guide (#47840)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/47483
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47840
Reviewed By: malfet
Differential Revision: D24951466
Pulled By: walterddr
fbshipit-source-id: 7530ec5a3aff7095978c330d9b78e58b10349373
