defineAction<TActionData> - allows to define a simple action creator
which produces actions with specified props.
const MyAction = defineAction<{ value: number; }>("MY ACTION");
Now action creator could be used for creating actions:
const actionInstance = MyAction({ value: 123 });
console.log(actionInstance.value); // Outputs 123
Also action creator could be used for checking actions for conforming a type:
const action: Action = ...
if (MyAction.is(action)) {
console.log(action.value); // action variable type now shrinked to { type: string; value: number }
}