Support for STATIC and MEDIA files

  - Updated the __init__ of `MinioBackend` to meet Django's custom storage system requirements
    "Django must be able to instantiate your storage system without any arguments"
    The `MinioBackend` class can be used as a value for `DEFAULT_FILE_STORAGE`
  - MinioBackendStatic: A new subclass of `MinioBackend` for supporting django-minio-backend as a static files storage
  - Added missing docstrings throughout the project
  - DjangoExampleApplication extended by `class GenericAttachment` for demonstrating a `FileField` without an explicit storage backend
  - DjangoExampleProject settings.py has been extended with the following new values:
    - MINIO_MEDIA_FILES_BUCKET
    - MINIO_STATIC_FILES_BUCKET
  - Updated README.md

django_minio_backend/models.py

@@ -300,7 +300,7 @@ def same_endpoints(self) -> bool:
     @property
     def bucket(self) -> str:
         """Get the configured bucket's [self.bucket] name"""
-        return self.bucket
+        return self._BUCKET_NAME
 
     @property
     def is_bucket_public(self) -> bool: