docs: def status(config):
      """time series lastest record time by account."""
      with open(config) as fh:
          config = yaml.safe_load(fh.read())
      jsonschema.validate(config, CONFIG_SCHEMA)
      last_index = get_incremental_starts(config, None)
      accounts = {}
      for (a, region), last in last_index.items():
          accounts.setdefault(a, {})[region] = last
      print(yaml.safe_dump(accounts, default_flow_style=False))