VALL-E new verson release

[jiaqili3]

✨ Description

adding more readme info of our new VALL-E implementation, and align VALLE V2 folder name with other Amphion files.

🚧 Related Issues

None

👨‍💻 Changes Proposed

• • We have changed the underlying implementation to Llama to provide better model performance, faster training speed, and more readable codes.
• • We provide more detailed README.md for reproducing our models with pretrained weights, training on LibriTTS, and future plans on improving the model.
• • We use a refined codec model name SpeechTokenizer as the codec, yielding better modeling quality than the original Encodec

🧑‍🤝‍🧑 Who Can Review?

@RMSnow

✅ Checklist

• • Code has been reviewed
• • Code complies with the project's code standards and best practices
• • Code has passed all tests
• • Code does not affect the normal use of existing features
• • Code has been commented properly
• • Documentation has been updated (if applicable)
• • Demo/checkpoint has been attached (if applicable)