docs: def write_title(self, title, level=1, id=None):
          """Writes a title header in the document body,
             with an optional depth level
          """
          if id:
              self.write('<h{lv} id="{id}">{title}</h{lv}>',
                         title=title, lv=level, id=id)
          else:
              self.write('<h{lv}>{title}</h{lv}>',
                         title=title, lv=level)