text: const fs = require('fs');
  const path = require('path');
  
  const indexFile = path.join('build', 'index.html');
  const error404File = path.join('build', '404.html');
  const cnameOriginal = path.join('CNAME');
  const cnameBuild = path.join('build', 'CNAME');
  
  fs.copyFile(indexFile, error404File, (err) => {
    if (err) throw err;
    console.log('build/index.html was copied to build/404.html');
  });
  
  fs.copyFile(cnameOriginal, cnameBuild, (err) => {
    if (err) throw err;
    console.log('CNAME was copied to build/CNAME');
  });
  // push