GitLab

Summary:
The `LibriMix` dataset is missing on the [documentation webpage](https://pytorch.org/audio/stable/datasets.html).

Pull Request resolved: https://github.com/pytorch/audio/pull/2351

Reviewed By: carolineechen

Differential Revision: D35926695

Pulled By: nateanl

fbshipit-source-id: 168aed3bb15510d1b1ec57d77727932e481aca48