title: Storybook Component-level css file not working
body: <p>I created a react app using create-react-app, and added a button component, a css for the button. When I load the story for the button, the styles are not loaded for the button. Pasting below, the related files. Is there any configuration that I am to do, to get this up and running with styles?</p>
  <p><a href="https://github.com/akhiltheguitarist/StoryBook/tree/master/storybookapp" rel="noreferrer">github repo for the project</a></p>
  <p>Component: index.js</p>
  <pre><code> import React, { Component } from 'react';
  import styles from './style.css';
  class CustomButton extends Component{
      render(){
          return (
              &lt;button className={styles.customButton}&gt;Hello&lt;/button&gt;     
          );
      }
  }
  export default CustomButton;
  </code></pre>
  <p>style.css:</p>
  <pre><code>.customButton {
      border: 1px solid red;
      padding: 10px;
      background-color: rgb(223, 19, 19);
  }
  </code></pre>
  <p>Story file:</p>
  <pre><code>import React from 'react';
  import CustomButton from '../../src/index';
  import { storiesOf } from '@storybook/react';
  
  
  const story = storiesOf(&quot;Custom button&quot;,module);
  
  story.addWithJSX(&quot;simple&quot;,() =&gt; &lt;CustomButton/&gt;);
  </code></pre>
  <p>System info:</p>
  <pre><code>Environment Info:
  
    System:
      OS: Windows 7 6.1.7601
      CPU: (2) x64 Intel(R) Core(TM) i3-2370M CPU @ 2.40GHz
    Binaries:
      Node: 10.16.0 - C:\Program Files\nodejs\node.EXE
      Yarn: 1.22.4 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
      npm: 6.9.0 - C:\Program Files\nodejs\npm.CMD
    Browsers:
      Chrome: 84.0.4147.125
    npmPackages:
      @storybook/addon-info: ^5.3.19 =&gt; 5.3.19
      @storybook/components: ^5.3.19 =&gt; 5.3.19
      @storybook/preset-create-react-app: ^3.1.4 =&gt; 3.1.4
      @storybook/react: ^5.3.19 =&gt; 5.3.19
  </code></pre>