docs: add missing code block closures in documentation files

packages/artplayer-vitepress/docs/en/advanced/built-in.md

@@ -227,6 +227,7 @@ art.on('ready', () => {
 		art.layers.show = false;
 	}, 1000);
 });
+```
 
 :::warning For `Component Configuration`, please refer to:
 

packages/artplayer-vitepress/docs/en/advanced/event.md

@@ -245,6 +245,7 @@ var art = new Artplayer({
 art.on('click', (event) => {
     console.info('click', event);
 });
+```
 
 ## `error`
 
@@ -722,6 +723,7 @@ var art = new Artplayer({
 art.on('subtitle', (state) => {
     console.log(state);
 });
+```
 
 ## `contextmenu`
 

packages/artplayer-vitepress/docs/en/advanced/global.md

@@ -235,6 +235,7 @@ var art = new Artplayer({
     container: '.artplayer-app',
     url: '/assets/sample/404.mp4',
 });
+```
 
 ## RECONNECT_SLEEP_TIME
 
@@ -478,6 +479,7 @@ var art = new Artplayer({
 
 art.contextmenu.show = true;
 art.setting.show = true;
+```
 
 ## FLIP
 

packages/artplayer-vitepress/docs/en/advanced/property.md

@@ -478,6 +478,7 @@ var art = new Artplayer({
         },
     ],
 });
+```
 
 :::warning Note