message: enable decorators in paly-ground
diff: @@ -22,7 +22,11 @@ const html = code => `<!DOCTYPE html>
  <script src="https://unpkg.com/apprun@es6/dist/apprun-html.js"></script>
  </head>
  <body>
  -<script type="text/babel" data-presets="es2017, react">
  +<script>
  + Babel.registerPlugin("d", [Babel.availablePlugins["proposal-decorators"], {legacy: true}]);
  + Babel.registerPlugin("c", [Babel.availablePlugins["proposal-class-properties"], {loose: true}]);
  +</script>
  +<script type="text/babel" data-presets="es2017, react" data-plugins="d, c">
  ${code}
  </script>
  </body>
  