title: Shopware 6: Module parse failed: Unexpected token after running `./psh.phar storefront:dev`
body: <p>I want to add some custom SCSS code to my Shopware 6 plugin. Therefore I created a <code>main.js</code> file as entry point and imported my custom SCSS file. After running <code>./psh.phar storefront:dev</code> I got following error from Webpack:</p>
  
  <pre><code>ERROR in /app/custom/plugins/MyTheme/src/Resources/storefront/styles/custom.scss 2:0
  Module parse failed: Unexpected token (2:0)
  You may need an appropriate loader to handle this file type.
     &gt; .test {
      | 
      | }
      npm ERR! code ELIFECYCLE
      npm ERR! errno 2
      npm ERR! sw-next-storefront@1.0.0 development: `NODE_ENV=development webpack --config webpack.config.js`
      npm ERR! Exit status 2
  </code></pre>