update demo

docs/index.html

@@ -21,7 +21,7 @@
     <section class="main">
         <div class="part-left">
             <header class="header">
-                <a href="./" class="logo">Artplayer.js</a>
+                <a href="./" class="logo">Artplayer.js<span class="version"></span></a>
                 <div class="menus">
                     <div class="item has-sub-menu">
                         Ecosystem