GitLab

Summary:
* Introduce the mini-index at `torchaudio.models` page.

https://output.circle-artifacts.com/output/job/25e59810-3866-4ece-b1b7-8a10c7a2286d/artifacts/0/docs/models.html

<img width="1042" alt="Screen Shot 2022-09-20 at 1 20 50 PM" src="https://user-images.githubusercontent.com/855818/191166816-83314ad1-8b67-475b-aa10-d4cc59126295.png">

<img width="1048" alt="Screen Shot 2022-09-20 at 1 20 58 PM" src="https://user-images.githubusercontent.com/855818/191166829-1ceb65e0-9506-4328-9a2f-8b75b4e54404.png">

Pull Request resolved: https://github.com/pytorch/audio/pull/2690

Reviewed By: carolineechen

Differential Revision: D39654948

Pulled By: mthrok

fbshipit-source-id: 703d1526617596f647c85a7148f41ca55fffdbc8