Add typescript definitions for getStorybook()

config/storybook.d.ts

@@ -1,7 +1,9 @@
 declare var module: any; // dangerous
 
+type RenderFunction = Function;
+
 interface StoryDecorator {
-  (story: Function, context: { kind: string, story: string }): Object | null;
+  (story: RenderFunction, context: { kind: string, story: string }): Object;
 }
 
 interface Story {
@@ -13,3 +15,15 @@ export function addDecorator(decorator: StoryDecorator): void;
 export function linkTo(name: string, ...params: any[]): void;
 export function storiesOf(name: string, module: any): Story;
 export function action(name: string, ...params: any[]): any;
+
+type StoryObject = {
+  name: string,
+  render: RenderFunction,
+};
+
+type StoryBucket = {
+  kind: string,
+  stories: StoryObject[],
+};
+
+export function getStorybook(): StoryBucket[];