function highlight(strings, ...values) {
    let str = '';
    strings.forEach((string, i) => {
      str += `${string} <span contenteditable class="hl">${values[i] || ''}</span>`;
    });
    return str;
  }

  const name = 'Snickers';
  const age = 100;

  const sentence = highlight`My dog's name is ${name} and he is ${age} years old`;
  document.body.innerHTML = sentence;
  console.log(sentence);
  
  请解释下highlight这个函数的两个参数，最好能详细点es6语法