### What problem does this PR solve?
- The API documentation lacks detailed error code explanations. Added
error code tables to `python_api_reference.md` and
`http_api_reference.md` to clarify possible error codes and their
meanings.
- Error handling in the codebase is inconsistent. Standardized error
handling logic in `sdk/python/ragflow_sdk/modules/chunk.py`.
- Improved API comments by adding standardized docstrings to enhance
code readability and maintainability.
### Type of change
- [x] Documentation Update
- [x] Refactoring
### What problem does this PR solve?
add tts api
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Zhedong Cen <cenzhedong2@126.com>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
feat: add rerank models to the project #724#162
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
