chore: Update window object property name to ArtplayerPluginVast

docs/assets/example/vast.js

@@ -0,0 +1,14 @@
+// npm i artplayer-plugin-vast
+// import ArtplayerPluginVast from 'artplayer-plugin-vast';
+
+var art = new Artplayer({
+    container: '.artplayer-app',
+    url: '/assets/sample/video.mp4',
+    fullscreen: true,
+    fullscreenWeb: true,
+    plugins: [
+        ArtplayerPluginVast({
+            url: '/assets/sample/vast.xml',
+        }),
+    ],
+});