Refine the multilingual front-end processing module

[lmxue]

✨ Description

We support espeak to extract IPA (International Phonetic Alphabet), which supports 100 languages, just shown in https://github.com/espeak-ng/espeak-ng/blob/master/docs/languages.md.

To highlight this support, this PR add comments for espeak tool with support of 100 languages to provide more helpful information. Also, Refine the multilingual front-end processing module, i.e., G2PModule, by passing the parameter of language to EspeakBackend.

🚧 Related Issues

#112

👨‍💻 Changes Proposed

• Pass the language parameter to init G2PModule in Amphion/processors/phone_extractor.py.
• Add the comment (We support espeak to extract IPA (International Phonetic Alphabet), which supports 100 languages, https://github.com/espeak-ng/espeak-ng/blob/master/docs/languages.md ) in Amphion/text/g2p_module.py and Amphion/config/tts.json

🧑‍🤝‍🧑 Who Can Review?

@RMSnow

🛠 TODO

None

✅ 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)