GitLab

Summary:
Adopt `:autosummary:` to various modules

    * torchaudio.compliance.kaldi
    * torchaudio.sox_effects
    * torchaudio.utils

Pull Request resolved: https://github.com/pytorch/audio/pull/2664

Reviewed By: nateanl

Differential Revision: D39841873

Pulled By: mthrok

fbshipit-source-id: ff4fa6976324fca5f35b737b715f976e2a722bac

- Addresses #549 #638 #786 
- Add `torchaudio` top level module doc
- Separate `torchaudio` top level module doc from `index.html`
- Add `backend` module doc.
- Remove `-> None` from function signature as it adds noise to documentation
- Changed function argument name of `torchaudio.backend.sox_io_backend.save` from `tensor` to `src`, so that it matches with the reset of backends.
- Tweak bunch of docstrings

* Add sox_utils module

* Make init/shutdown thread safe

* Add sox effects implementation

* Add test for sox effects

* Update docstrings and add examples