Add Function forceReRender() to Definitions (#27051)

types/storybook__react/index.d.ts

@@ -25,6 +25,7 @@ export function configure(fn: () => void, module: NodeModule): void;
 export function setAddon(addon: object): void;
 export function storiesOf(name: string, module: NodeModule): Story;
 export function storiesOf<T>(name: string, module: NodeModule): Story & T;
+export function forceReRender(): void;
 
 export interface StoryObject {
     name: string;

types/storybook__react/storybook__react-tests.tsx

@@ -1,8 +1,10 @@
 import * as React from 'react';
-import { storiesOf, setAddon, addDecorator, configure, getStorybook, RenderFunction, Story } from '@storybook/react';
+import { storiesOf, setAddon, addDecorator, configure, getStorybook, RenderFunction, Story, forceReRender } from '@storybook/react';
 
 const Decorator = (story: RenderFunction) => <div>{story()}</div>;
 
+forceReRender();
+
 storiesOf('Welcome', module)
     // local addDecorator
     .addDecorator(Decorator)