text: const path = require('path');
  const merge = require('webpack-merge');
  const CopyWebpackPlugin = require('copy-webpack-plugin');
  const createDefaultConfigs = require('./modern-and-legacy-config');
  
  const configs = createDefaultConfigs({
    input: path.resolve(__dirname, '../index.html'),
  });
  
  if (Array.isArray(configs)) {
    module.exports = [
      merge(configs[0], {
        plugins: [new CopyWebpackPlugin(['demo/**/*.txt'])],
      }),
      configs[1],
    ];
  } else {
    module.exports = configs;
  }
  