API: create dataset (#1106)

### 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>

sdk/python/README.md

@@ -1 +1,41 @@
-# ragflow
+# python-ragflow
+
+# update python client
+
+- Update "version" field of [project] chapter
+- build new python SDK
+- upload to pypi.org
+- install new python SDK
+
+# build python SDK
+
+```shell
+rm -f dist/* && python setup.py sdist bdist_wheel
+```
+
+# install python SDK
+```shell
+pip uninstall -y ragflow && pip install dist/*.whl
+```
+
+This will install ragflow-sdk and its dependencies.
+
+# upload to pypi.org
+```shell
+twine upload dist/*.whl
+```
+
+Enter your pypi API token according to the prompt.
+
+Note that pypi allow a version of a package [be uploaded only once](https://pypi.org/help/#file-name-reuse). You need to change the `version` inside the `pyproject.toml` before build and upload.
+
+# using
+
+```python
+
+```
+
+# For developer
+```shell
+pip install -e .
+```