Support typing #48
Description
Since sqlalchemy 2.0 supports mapped columns, is it possible to add typing support to this library. Currently, if you try :
foo_json: Mapped[Optional[Dict[Any, Any]]] = mapped_column(NestedMutableJson)
You get the following warning:
Argument type is partially unknown Argument corresponds to parameter "__name_pos" in function "mapped_column" Argument type is "TypeEngine[Unknown]"Pylance[reportUnknownArgumentType](https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportUnknownArgumentType) (variable) NestedMutableJson: TypeEngine[_T@as_mutable]