docs: def read_config(file_name):
      """Read configuration."""
  
      config = {}
      for name in (['.pyspelling.yml', '.spelling.yml'] if not file_name else [file_name]):
          if os.path.exists(name):
              if not file_name and name == '.spelling.yml':
                  warn_deprecated(
                      "Using '.spelling.yml' as the default is deprecated. Default config is now '.pyspelling.yml'"
                  )
              with codecs.open(name, 'r', encoding='utf-8') as f:
                  config = yaml_load(f.read())
              break
      return config