code: def add_markdown_cell(self, content, tags=None):
          
          self.notebook["cells"].append(nb.v4.new_markdown_cell(content, **{"metadata":
                                                                            {"tags": tags}}))
docs: Class method responsible for adding a markdown cell with content 'content' to the
          Notebook object.
  
          ----------
          Parameters
          ----------
          content : str
              Text/HTML code/... to include in the markdown cell (triple quote for multiline text).
  
          tags : list
              A list of tags to include in the markdown cell metadata.