update index.html title to DPlayer docs

docs/index.html

@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge" />
   <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0" />
-  <title>Docute</title>
+  <title>DPlayer docs</title>
   <link rel="stylesheet" href="https://unpkg.com/docute@latest/dist/docute.css">
   <style>
     .weibo-icon {