需求：導出瀏覽器工作臺的日志，導出成txt文件；

const filename = '臨時日志';
      const qhyhLog = 'abcdefg'; // 需要導出的字符串
      const element = document.createElement('a');
      element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(qhyhLog));
      element.setAttribute('download', filename);
      element.style.display = 'none';
      document.body.appendChild(element);
      element.click();
      document.body.removeChild(element);