code: function generateScript(source) {
          var script = document.createElement('script');
          script.type = 'text/javascript';
          script.src = encodeURI(source);
          script.setAttribute('async', '');
          script.setAttribute('charset', 'utf-8');
          return script;
        }
docs: @function generateScript
  Generates script tag element
  
  @param {string} source
  @returns HTMLElement