How do I add Webpack config to Rails?

I'm following the installation guide of Vuetify and it requires me to add the following to webpack.config.js but since Rails has no such file, how should I go about adding these rules?

module.exports = {
  rules: [
    {
      test: /\.s(c|a)ss$/,
      use: [
        'vue-style-loader',
        'css-loader',
        {
          loader: 'sass-loader',
          // Requires sass-loader@^7.0.0
          options: {
            implementation: require('sass'),
            fiber: require('fibers'),
            indentedSyntax: true // optional
          },
          // Requires sass-loader@^8.0.0
          options: {
            implementation: require('sass'),
            sassOptions: {
              fiber: require('fibers'),
              indentedSyntax: true // optional
            },
          },
        },
      ],
    },
  ],
}