Add Storj DCS as an explicit endpoint for S3-compatible storage (#687)

* added section for

* Update index.rst

Include Storj DCS as an explicit S3 Compatible storage option

* remove whitespace

Co-authored-by: Martin Durant <martindurant@users.noreply.github.com>

docs/source/index.rst

@@ -211,6 +211,26 @@ For a self-hosted MinIO instance:
          }
       )
 
+For Storj DCS via the `S3-compatible Gateway <https://docs.storj.io/dcs/getting-started/quickstart-aws-sdk-and-hosted-gateway-mt>`_:
+
+.. code-block:: python
+
+   # When relying on auto discovery for credentials
+   >>> s3 = s3fs.S3FileSystem(
+         anon=False,
+         client_kwargs={
+            'endpoint_url': 'https://gateway.storjshare.io'
+         }
+      )
+   # Or passing the credentials directly
+   >>> s3 = s3fs.S3FileSystem(
+         key='accesskey...',
+         secret='asecretkey...',
+         client_kwargs={
+            'endpoint_url': 'https://gateway.storjshare.io'
+         }
+      )
+
 For a Scaleway s3-compatible storage in the ``fr-par`` zone:
 
 .. code-block:: python