title: customize-cra - Support for the experimental syntax 'jsx' isn't currently enabled
body: <p>I am using react-app-rewired to configure my CRA project as I was having issues with 2 co-existing versions of React which I'm sure is a very common use-case for <code>react-app-rewired/customize-cra</code>.</p>
  <p>Everything has been fine until I required installing <code>react-native-calendars</code> as a dependency.
  As you can see in my <code>addBabelPlugins</code> config; I have needed to install <code>@babel/plugin-proposal-class-properties</code> to transpile the libraries' components... I am now however getting an error that complains about JSX in my codebase which I thought would already be handled by CRA in the first place and seeing as we are overwriting/extending CRA with <code>react-app-rewired</code> i didn't think I would need to add additional plugins/presets such as <code>@babel/preset-react</code> &amp; <code>@babel/plugin-syntax-jsx</code>...</p>
  <p>can somebody point me in the right direction? I'm hoping this issue is common and I have just searched the issues page poorly.</p>
  <p>Thank you</p>
  <h3>Info</h3>
  <pre class="lang-rb prettyprint-override"><code>react@17.0.1
  react-scripts@3.4.3
  customize-cra@1.0.0 
  npm@6.14.9
  node@14.8.0
  </code></pre>
  <h3>Error</h3>
  <pre class="lang-rb prettyprint-override"><code>Failed to compile.
  
  ./src/App.js
  SyntaxError: /Users/.../src/App.js: Support for the experimental syntax 'jsx' isn't currently enabled (28:5):
  
    26 | 
    27 |   return (
  &gt; 28 |     &lt;Router&gt;
       |     ^
    29 |       &lt;Switch&gt;
  
  Add @babel/preset-react (https://git.io/JfeDR) to the 'presets' section of your Babel config to enable transformation.
  If you want to leave it as-is, add @babel/plugin-syntax-jsx (https://git.io/vb4yA) to the 'plugins' section to enable parsing.
  </code></pre>
  <h3>config-overrides.js</h3>
  <pre class="lang-js prettyprint-override"><code>const {
    override,
    addWebpackAlias,
    babelInclude,
    addBabelPresets,
    addBabelPlugins,
  } = require('customize-cra');
  
  module.exports = override(
    babelInclude([
      require.resolve('./src'),
      require.resolve('./node_modules/react-native-calendars'),
    ]),
    ...addBabelPresets(
      '@babel/preset-react',
    ),
    ...addBabelPlugins(
      '@babel/plugin-proposal-class-properties', // &lt;~ needed for react-native-calendars
      '@babel/plugin-syntax-jsx',
    ),
    addWebpackAlias({
      react: require.resolve('./node_modules/react'),
    }),
  );
  </code></pre>
  <p>Original issue <a href="https://github.com/arackaf/customize-cra/issues/279" rel="nofollow noreferrer">here</a></p>