website/playground/util.js/getCodemirrorMode
export function getCodemirrorMode(parser) {
  switch (parser) {
    case "css":
    case "less":
    case "scss":
      return "css";
    case "graphql":
      return "graphql";
    case "markdown":
      return "markdown";
    default:
      return "jsx";
  }
}