code: def md_options_to_metadata(options):
      
      metadata = parse_md_code_options(options)
  
      if metadata:
          language = metadata[0][0]
          for lang in _JUPYTER_LANGUAGES + ['julia', 'scheme', 'c++']:
              if language.lower() == lang.lower():
                  return lang, dict(metadata[1:])
  
      return None, dict(metadata)
docs: Parse markdown options and return language and metadata