Loving this project.

I feel like this project would benefit from a short quick start tutorial that demonstrate common methods such as:

Create item

    mutation = Operation(schema.Mutation)  # note 'schema.'
    mutation.create_item(input=dict(id="23432")).__fields__()

List items with filter

    op = Operation(schema.Query)  # note 'schema.'
    op.list_items(filter={"number_id": {'eq': 123456 }})

Making HTTP Calls to AWS AppSync (Managed Graphql Service)

  query = Operation(schema.Query)
  items = query.list_items()

  query = bytes(query).decode("utf-8")

  post_data = json.dumps({"query": query}).encode("utf-8")

  headers = {}
  headers["Accept"] = "application/json; charset=utf-8"

  auth = AWS4Auth(
        access_key_id,
        secret_access_key,
        region_name,
        "appsync",
        session_token=session_token,
    )

  response = requests.post(url, auth=auth, data=post_data, headers=headers)

I'll add more examples as I work them out =)