Snac

What's Changed
* add encode/decode methods (codes to audio) by hubertsiuzdak in https://github.com/hubertsiuzdak/snac/pull/11


**Full Changelog**: https://github.com/hubertsiuzdak/snac/compare/v1.1.0...v1.2.0

- new model `snac_24khz` (speech codec):

| Model | Bitrate | Sample Rate | Params | Recommended use case |
|-----------------------------------------------------------------------------|-----------|-------------|--------|--------------------------|
| [hubertsiuzdak/snac_24khz](https://huggingface.co/hubertsiuzdak/snac_24khz) | 0.98 kbps | 24 kHz | 19.8 M | 🗣️ Speech |

- Update architecture
- New models available:

| Model | Bitrate | Sample Rate |
|-----------------------------------------------------------------------------|----------|-------------|
| [hubertsiuzdak/snac_32khz](https://huggingface.co/hubertsiuzdak/snac_32khz) | 1.9 kbps | 32 kHz |
| [hubertsiuzdak/snac_44khz](https://huggingface.co/hubertsiuzdak/snac_44khz) | 2.6 kbps | 44 kHz |