chore: Update window object property name to ArtplayerPluginVast

docs/index.html

@@ -61,6 +61,10 @@
                             <a
                                 href="/?libs=./uncompiled/artplayer-plugin-chromecast/index.js&example=chromecast">artplayer-plugin-chromecast</a>
                         </li>
+                        <li>
+                            <a
+                                href="/?libs=./uncompiled/artplayer-plugin-vast/index.js&example=vast">artplayer-plugin-vast</a>
+                        </li>
                     </ul>
                     <ul>
                         <li class="title">Library</li>