Request: ability to restrict the types for meta #70

I would like to have a strong typing for the meta attribute on my actions.

I tried to define my own action() method with stricter types:

import { action as originalAction } from "typesafe-actions"

export const action: (
  type: string,
  payload?: any,
  meta?: ActionMetaType,
) => PayloadMetaAction<string, any, ActionMetaType> = originalAction

If I do this, I am loosing the type on my AppAction union type, for example:

error TS2339: Property 'payload' does not exist on type 'AppAction'.
  Property 'payload' does not exist on type '{ type: string; meta: ActionMetaType; }'.

I am not sure what is the best way to achieve this, but it would be really awesome to be able to do it!