Change an official example custom webpack.config.js to be async
Change an official example custom webpack.config.js to be async

kadirahq/react-storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook,storybooks/react-storybook,storybooks/storybook,kadirahq/react-storybook,storybooks/react-storybook,storybooks/react-storybook,storybooks/storybook,storybooks/react-storybook,storybooks/storybook