Fix link to Storybook docs (#2521)

Author: shilman

packages/react-scripts/template/README.md

@@ -1359,7 +1359,7 @@ Learn more about React Storybook:
 
 * Screencast: [Getting Started with React Storybook](https://egghead.io/lessons/react-getting-started-with-react-storybook)
 * [GitHub Repo](https://github.com/storybooks/storybook)
-* [Documentation](https://storybook.js.org/docs/react-storybook/basics/introduction/)
+* [Documentation](https://storybook.js.org/basics/introduction/)
 * [Snapshot Testing UI](https://github.com/storybooks/storybook/tree/master/addons/storyshots) with Storybook + addon/storyshot
 
 ## Making a Progressive Web App