Refactor artplayerPluginLibass to use ES6 syntax

docs/assets/example/libass.js

@@ -1,79 +1,9 @@
 var art = new Artplayer({
     container: '.artplayer-app',
     url: '/assets/sample/video.mp4',
-    poster: '/assets/sample/poster.jpg',
-    volume: 0.5,
-    isLive: false,
-    muted: false,
-    autoplay: false,
-    pip: true,
-    autoSize: true,
-    autoMini: true,
-    screenshot: true,
-    setting: true,
-    loop: true,
-    flip: true,
-    playbackRate: true,
-    aspectRatio: true,
-    fullscreen: true,
     fullscreenWeb: true,
-    subtitleOffset: true,
-    miniProgressBar: true,
-    mutex: true,
-    backdrop: true,
-    playsInline: true,
-    autoPlayback: true,
-    airplay: true,
-    theme: '#23ade5',
-    lang: navigator.language.toLowerCase(),
-    moreVideoAttr: {
-        crossOrigin: 'anonymous',
-    },
-    settings: [
-        {
-            width: 200,
-            html: 'Subtitle',
-            tooltip: 'Bilingual',
-            icon: '<img width="22" heigth="22" src="/assets/img/subtitle.svg">',
-            selector: [
-                {
-                    html: 'Display',
-                    tooltip: 'Show',
-                    switch: true,
-                    onSwitch: function (item) {
-                        item.tooltip = item.switch ? 'Hide' : 'Show';
-                        art.subtitle.show = !item.switch;
-                        return !item.switch;
-                    },
-                },
-                {
-                    html: 'Style Test',
-                    url: '/assets/sample/style-test.ass',
-                },
-                {
-                    default: true,
-                    html: 'Bilingual',
-                    url: '/assets/sample/subtitle.ass',
-                },
-                {
-                    html: 'subtitle.srt',
-                    url: '/assets/sample/subtitle.srt',
-                },
-            ],
-            onSelect: function (item) {
-                art.subtitle.switch(item.url, {
-                    name: item.html,
-                });
-                return item.html;
-            },
-        },
-    ],
     subtitle: {
-        url: '/assets/sample/subtitle.ass',
-        style: {
-            color: '#48aff0',
-            fontSize: '16px',
-        },
+        url: '/assets/sample/style-test.ass',
     },
     plugins: [
         artplayerPluginLibass({