text: Title: Quick Start Tutorial Needed
  Body: 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 =)
  