docs: def get_package_dir(nb_path):
      """Return the package directory for a Notebook that has an embeded Metatab doc, *not* for
      notebooks that are part of a package """
      doc = get_metatab_doc(nb_path)
      doc.update_name(force=True, create_term=True)
      pkg_name = doc['Root'].get_value('Root.Name')
      assert pkg_name
  
      return ensure_source_package_dir(nb_path, pkg_name), pkg_name