Hls quality (#409)

* update docs

docs/assets/example/hls.quality.js

@@ -0,0 +1,28 @@
+var art = new Artplayer({
+    container: '.artplayer-app',
+    url: 'https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8',
+    setting: true,
+    plugins: [
+        artplayerPluginHlsQuality({
+            // Show quality in control
+            control: true,
+            // Show quality in setting
+            setting: true,
+            // Name of setting panel
+            name: 'Hls Quality',
+        }),
+    ],
+    customType: {
+        m3u8: function (video, url) {
+            if (Hls.isSupported()) {
+                art.hls = new Hls();
+                art.hls.loadSource(url);
+                art.hls.attachMedia(video);
+            } else if (video.canPlayType('application/vnd.apple.mpegurl')) {
+                video.src = url;
+            } else {
+                art.notice.show = 'Does not support playback of m3u8';
+            }
+        },
+    },
+});