docs: def create_config(config_fname, override_url=None):
      '''
      Create the config file from the defaults under the given name.
      '''
      config_path = os.path.dirname(config_fname)
      os.makedirs(config_path, exist_ok=True)
  
      # Consider override URL. Only used by test suite runs
      settings = DEFAULT_SETTINGS_FLAT
      if override_url:
          settings['url'] = override_url
  
      # Create fresh config file, including new UUID
      with open(config_fname, 'wt') as config:
          config.write(DEFAULT_FILE_CONTENT.format(**settings))
      return True