### What problem does this PR solve?
_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._
### Type of change
- [x] Documentation Update
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
Refactor Chunk API
#2846
### Type of change
- [x] Refactoring
---------
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
### Type of change
- [x] Documentation Update
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
Refactor API for document and session.
### Type of change
- [x] Refactoring
---------
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
### What problem does this PR solve?
Refactor Chat API
### Type of change
- [x] Refactoring
---------
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
### What problem does this PR solve?
Refactor Dataset API
### Type of change
- [x] Refactoring
---------
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
writinwaters
liuhua