message: demo: Add head tag
diff: <!DOCTYPE html>
  +<html>
  +
  +<head>
  + <meta charset="utf-8" />
  + <meta name="viewport"
  + content="width=device-width,initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0,user-scalable=no">
  + <meta name="description" content="Moveable is Draggable! Resizable! Scalable! Rotatable!" />
  + <meta property="og:title" content="Moveable is Draggable! Resizable! Scalable! Rotatable!">
  + <meta property="og:url" content="http://daybrush.com/moveable">
  + <meta property="og:image" content="http://daybrush.com/moveable/images/moveable1920x1080.png">
  + <meta property="og:description" content="Moveable is Draggable! Resizable! Scalable! Rotatable!">
  + <meta name="twitter:card" content="summary">
  + <meta name="twitter:title" content="Moveable is Draggable! Resizable! Scalable! Rotatable!">
  + <meta name="twitter:url" content="http://daybrush.com/moveable">
  + <meta name="twitter:image" content="http://daybrush.com/moveable/images/moveable1920x1080.png">
  + <meta name="twitter:description" content="Moveable is Draggable! Resizable! Scalable! Rotatable!">
  + <meta name="theme-color" content="#f5f5f5">
  + <title>Moveable is Draggable! Resizable! Scalable! Rotatable!</title>
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.8/styles/default.min.css">
  <link rel="stylesheet" type="text/css" href="./dist/index.css" />
  +</head>
  +
  +<body>
  +
  <div class="page">
  <div class="container">
  <div class="moveable"><span>Moveable</span></div>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.8/highlight.min.js"></script>
  <script src="./dist/index.js"></script>
  +</body>
  +</html>
  