Clean up mvlgamma doc (including a weird way to link to reference) (#32667)
Summary:
Intentionally left blank
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32667
Differential Revision: D19594683
Pulled By: ezyang
fbshipit-source-id: 5a6eb0a74f569d3c0db2a35e0ed4b329792a18e4