message: add dev tools to play
diff: @@ -19,6 +19,7 @@ const html = code => `<!DOCTYPE html>
  }
  </style>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
  + <script src="dist/apprun-dev-tools.js"></script>
  <script src="dist/apprun-html.js"></script>
  </head>
  <body>
  