### What problem does this PR solve?

SDK for Assistant
#1102 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Co-authored-by: Feiue <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

Complete DataSet SDK implementation
#1102

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Feiue <10215101452@stu.ecun.edu.cn>

### What problem does this PR solve?

Complete implementation of dataset SDK.
#1102

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Feiue <10215101452@stu.ecun.edu.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

### What problem does this PR solve?

Added the ability to create and update dataset for SDK

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: root <root@xwg>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

### What problem does this PR solve?

You can use sdk to create a dataset

### Type of change

- [x] New Feature

---------

Co-authored-by: root <root@xwg>

### What problem does this PR solve?

Aims to stop the process of parsing.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Adds the doc for the newly added API method.

### Type of change


- [x] Documentation Update

### What problem does this PR solve?

show status of parsing.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Make the document start parsing.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Adds download_document api

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Adds the API method of updating documents.


### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Adds the api of listing documentation.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Adds the functionality of deleting documentation

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Polish grammar.

### Type of change

- [x] Documentation Update

### What problem does this PR solve?

API: Adds the feature of uploading document.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Added get_dataset and update_dataset API.
Fixed delete_dataset.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update

### What problem does this PR solve?

This PR added ragflow_api.md and more tests for API.

### Type of change

- [x] Documentation Update
- [x] Other (please describe): tests

### What problem does this PR solve?

This PR have completed both HTTP API and Python SDK for
'delete_dataset". In addition, there are tests for it.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

This PR have completed both HTTP API and Python SDK for 'list_dataset".
In addition, there are tests for it.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

This PR have finished 'create dataset' of both HTTP API and Python SDK.
HTTP API:
```
curl --request POST --url http://<HOST_ADDRESS>/api/v1/dataset   --header 'Content-Type: application/json' --header 'Authorization: <ACCESS_KEY>' --data-binary '{
  "name": "<DATASET_NAME>"
}'
```

Python SDK:
```
from ragflow.ragflow import RAGFLow
ragflow = RAGFLow('<ACCESS_KEY>', 'http://127.0.0.1:9380')
ragflow.create_dataset("dataset1")

```

TODO: 
- ACCESS_KEY is the login_token when user login RAGFlow, currently.
RAGFlow should have the function that user can add/delete access_key.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

### What problem does this PR solve?

delete SDK repo and edit readme

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Added delete_dataset method and test for it.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

### What problem does this PR solve?

Add create_dataset method, test for it, and update SDK->sdk.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Signed-off-by: cecilia-uu <konghui1996@163.com>