docs: def idx_name_to_num(L):
      """
      Switch from index-by-name to index-by-number.
      :param dict L: Metadata
      :return dict: Modified metadata
      """
      logger_jsons.info("enter idx_name_to_num")
  
      # Process the paleoData section
      if "paleoData" in L:
          L["paleoData"] = _export_section(L["paleoData"], "paleo")
  
      # Process the chronData section
      if "chronData" in L:
          L["chronData"] = _export_section(L["chronData"], "chron")
  
      logger_jsons.info("exit idx_name_to_num")
      return L