fix(docs): `torch.add` and `torch.mul` (#54672)
Summary:
fixes https://github.com/pytorch/pytorch/issues/39425
https://11813267-65600975-gh.circle-artifacts.com/0/docs/generated/torch.add.html
https://11813267-65600975-gh.circle-artifacts.com/0/docs/generated/torch.mul.html
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54672
Reviewed By: ailzhang
Differential Revision: D27328523
Pulled By: zou3519
fbshipit-source-id: c804e3312b63ee209fef8bdfd8a92d46a345aa21
