Add more details for README (#107)

* Add more details for README

* Add init description to README

README.md

@@ -1,2 +1,90 @@
 # tosfs
-tosfs is a tos Python client that implements the fsspec interface.
+
+[![PyPI version](https://badge.fury.io/py/tosfs.svg)](https://pypi.python.org/pypi/tosfs/)
+![Build](https://github.com/volcengine/tosfs/workflows/CI/badge.svg)
+
+TOSFS builds on [Volcengine TOS Python SDK](https://github.com/volcengine/ve-tos-python-sdk) to provide a convenient Python filesystem interface for [TOS（Tinder Object Storage）](https://www.volcengine.com/docs/6349/74820).
+
+## Installation(TODO)
+
+You can install tosfs via [pip](https://pip.pypa.io/) from [PyPI](https://pypi.org/):
+
+```shell
+$ pip install tosfs
+```
+
+## Quick Start
+
+### Init FileSystem
+
+* Init via `ak/sk`
+
+```python
+from tosfs.core import TosFileSystem
+from tos import StaticCredentialsProvider
+
+tosfs = TosFileSystem(
+    key='ak',
+    secret='sk',
+    endpoint_url='http://tos-cn-beijing.volces.com',
+    region='cn-beijing',
+    credentials_provider=StaticCredentialsProvider, # optional
+)
+```
+
+* Init via system env
+
+make sure these envs take effect:
+
+```shell
+export TOS_ACCESS_KEY=' your ak here '
+export TOS_SECRET_KEY=' your sk here '
+export TOS_ENDPOINT='http://tos-cn-beijing.volces.com'
+export TOS_REGION='cn-beijing'
+```
+then init `TosFileSystem` by setting `credentials_provider` to `EnvCredentialsProvider`
+
+```python
+import os
+from tosfs.core import TosFileSystem
+from tos import EnvCredentialsProvider
+
+tosfs = TosFileSystem(
+    endpoint_url=os.environ.get("TOS_ENDPOINT"),
+    region=os.environ.get("TOS_REGION"),
+    credentials_provider=EnvCredentialsProvider, # must
+)
+```
+
+### Access FS and file operation APIs
+
+After getting the instance of `TosFileSystem` by following the above guidance,
+now we can access fs and file operation apis, e.g.
+
+```python
+# list
+tosfs.ls("")
+tosfs.ls("mybucket", detail=False)
+tosfs.ls("mybucket/rootpath/", detail=False)
+
+# file read/write
+with tosfs.open('bucket/root/text.txt', mode='wb') as f:
+    f.write('hello tosfs!')
+
+with tosfs.open('bucket/root/text.txt', mode='rb') as f:
+    content = f.read()
+    print(content)
+```
+
+## Contributing
+Contributions are very welcome. To learn more, see the [Contributor Guide](https://github.com/volcengine/tosfs/blob/main/CONTRIBUTING.md).
+
+## License
+Distributed under the terms of the [Apache 2.0 license](https://github.com/volcengine/tosfs/blob/main/LICENSE), Tosfs is free and open source software.
+
+## Issues
+If you encounter any problems, please [file an issue](https://github.com/volcengine/tosfs/issues/new/choose) along with a detailed description.
+
+
+
+