Update credits.

Author: m-ou-se

public/credits/index.html

@@ -519,7 +519,7 @@ <h1>See you tomorrow</h1>
 </div>
 </div>
 
-<audio id="audio"><source src="music.mp3" type="audio/mpeg"></audio>
+<audio id="audio" preload="auto"><source src="music.mp3" type="audio/mpeg"></audio>
 
 </body>
 </html>