code: def add_javascripts(self, *js_files):
          
          # create the script tag if don't exists
          if self.main_soup.script is None:
              script_tag = self.main_soup.new_tag('script')
              self.main_soup.body.append(script_tag)
  
          for js_file in js_files:
              self.main_soup.script.append(self._text_file(js_file))
docs: add javascripts files in HTML body