text: Title: Minor fix for Meta docs
  Body: The documentation says that attribute name of Meta defaults to `the lower-case of the model’s class name` but it actually defaults to the [lower-case of the model's table name](https://github.com/biosustain/potion/blob/af3f52173e97ef41bddfa8f4775280c9b8d3188d/flask_potion/contrib/alchemy/manager.py#L60).
  