[docs] add Oracle cloud usage (#1086)

docs/backends/oracle-cloud.rst

@@ -0,0 +1,32 @@
+Oracle Cloud
+=============
+
+Oracle cloud provides S3 compatible object storage. To use it follow the instructions in the :doc:`Amazon S3 docs <amazon-S3>` on how to configure *DEFAULT_FILE_STORAGE* and *STATICFILES_STORAGE* and set the following
+configurations on settings.py
+
+- Create a `Customer Secret Key`_
+- Use generated key as ``AWS_SECRET_ACCESS_KEY``
+- And the value in the *Access Key* column as ``AWS_ACCESS_KEY_ID``
+- Set ``AWS_STORAGE_BUCKET_NAME`` with your bucket name
+- Set ``AWS_S3_REGION_NAME`` with the current region
+
+And last but most importantly set the ``AWS_S3_ENDPOINT_URL`` with:
+
+    ``https://{ORACLE_NAMESPACE}.compat.objectstorage.{ORACLE_REGION}.oraclecloud.com``
+
+The ``ORACLE_NAMESPACE`` value can be found on the bucket details page
+
+
+References
+==========
+
+- `Customer Secret Key`_
+- `Amazon S3 Compatibility API docs`_
+- `Amazon S3 Compatibility API endpoints`_
+- `Oracle object storage namespaces docs`_
+
+
+.. _Oracle object storage namespaces docs: https://docs.oracle.com/en-us/iaas/Content/Object/Tasks/understandingnamespaces.htm#Understanding_Object_Storage_Namespaces
+.. _Amazon S3 Compatibility API docs: https://docs.oracle.com/en-us/iaas/Content/Object/Tasks/s3compatibleapi.htm#
+.. _Amazon S3 Compatibility API endpoints: https://docs.oracle.com/en-us/iaas/api/#/en/s3objectstorage/20160918/
+.. _Customer Secret Key: https://docs.oracle.com/en-us/iaas/Content/Identity/Tasks/managingcredentials.htm#To4