fix link in iframe mode

Author: wayou

audio_visualizer_single_page_version.html

@@ -40,7 +40,7 @@
             </div>
         </div>
          <footer>
-            <small>Star me on <a href="https://github.com/Wayou/HTML5_Audio_Visualizer">GitHub</a></small>
+            <small>Star me on <a href="https://github.com/Wayou/HTML5_Audio_Visualizer" target="_blank">GitHub</a></small>
         </footer>
         <script type="text/javascript">
        /*

index.html

@@ -19,7 +19,7 @@
             </div>
         </div>
         <footer>
-            <small>Star me on <a href="https://github.com/Wayou/HTML5_Audio_Visualizer">GitHub</a></small>
+            <small>Star me on <a href="https://github.com/Wayou/HTML5_Audio_Visualizer"  target="_blank">GitHub</a></small>
         </footer>
         <script type="text/javascript" src="js/html5_audio_visualizer.js"></script>
     </body>