[docs] Fix back quote rendering in loss modules docs (#45662)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/42855. Previously, back quotes weren't rendering correctly in
equations. This is because we were quoting things like `'mean'`. In
order to backquote properly in latex in text-mode, the back-quote needs
to be written as a back-tick.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45662
Test Plan:
- built docs locally and viewed the changes.
For NLLLoss (which is not the original module mentioned in the issue, but it has the same problem), we can see how the back quotes now render properly:
Reviewed By: glaringlee
Differential Revision: D24049880
Pulled By: zou3519
fbshipit-source-id: 61a1257994144549eb8f29f19d639aea962dfec0
