AsyncConstructor needs to be exported

[Neale Upstone]

Typescript emits TS4023 error because it cannot find the 'shape' of the function when emitting type declarations. Exporting AsyncConstructor solves this.

For example when I write:

import {createInstance} from "react-async";
export const AsyncData = createInstance<MyData>({});

Typescript wants to generate:

export declare const AsyncData: import("react-async").AsyncConstructor<MyData>;

However this is not possible because AsyncConstructor is not exported