title: Webpack Encore - $ is not defined
body: <p>I followed the documentation to make Webpack Encore work in my project.
  Imported js files in webpack.config.js work fine but I have an issue in page-specific js : <code>$ is not defined</code>.</p>
  
  <p><strong>Webpack.config.js</strong> :</p>
  
  <pre><code>const Encore = require('@symfony/webpack-encore');
  var webpack = require('webpack');
  
  Encore
  .setOutputPath('public/build/')
  .setPublicPath('http://localhost/tharmo/public/build')
  .setManifestKeyPrefix('build/')
  .cleanupOutputBeforeBuild()
  .enableSourceMaps(!Encore.isProduction())
  .autoProvidejQuery()
  
  .createSharedEntry('vendor', [
      './assets/js/custom.js',
      'materialize-css',
  ])
  .addEntry('app', './assets/js/app.js')
  .addEntry('statistiques', './assets/js/statistiques.js')
  .addPlugin(new webpack.ProvidePlugin({
      $: 'jquery',
      jQuery: 'jquery',
      'window.jQuery': 'jquery',
  }))
  
  .enableSassLoader()
  ;
  
  module.exports = Encore.getWebpackConfig();
  </code></pre>
  
  <p><strong>base.html.twig</strong> :</p>
  
  <pre><code>&lt;script src="{{ asset('build/manifest.js') }}"&gt;&lt;/script&gt;
  &lt;script src="{{ asset('build/vendor.js') }}"&gt;&lt;/script&gt;
  &lt;script type="text/javascript" src="{{ asset('build/app.js') }}"&gt;&lt;/script&gt;
  &lt;script&gt;
      $(document).ready(function () {
          getNotifications(1);
      });
  &lt;/script&gt;
  </code></pre>
  
  <p><code>$(document).ready</code> doesn't work.</p>