Doc language fixes (#41643)
Summary:
Updates doc for abs, acos, and isinf for clarity and consistency.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41643
Reviewed By: ngimel
Differential Revision: D22622957
Pulled By: mruberry
fbshipit-source-id: 040f01b4e101153098577bf10dcd569b679aae2c
