Makes elementwise comparison docs more consistent (#41626)
Summary:
- Removes outdated language like "BoolTensor"
- Consistently labels keyword arguments, like out
- Uses a more natural string to describe their return type
- A few bonus fixes
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41626
Reviewed By: ngimel
Differential Revision: D22617322
Pulled By: mruberry
fbshipit-source-id: 03cc3562b78a07ed30bd1dc7936d7a4f4e31f01d
