fixed unique arguments documentation (#66132)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66132
Differential Revisi
<img width="875" alt="Screen Shot 2021-10-05 at 12 10 39 PM" src="https://user-images.githubusercontent.com/17888388/136276286-3df20681-7b7a-4a91-97d6-4f1ac3722121.png">
on: [D31397746](https://our.intern.facebook.com/intern/diff/D31397746/)
Test Plan: Imported from OSS
Reviewed By: gchanan
Differential Revision: D31734476
Pulled By: samdow
fbshipit-source-id: 8999443c7f9b24394d7543652b8350261c1f8b3a
