feat: add markers (#2386)

Co-authored-by: fengshuo <fengshuo@bilibili.com>

src/js/config/defaults.js

@@ -391,6 +391,10 @@ const defaults = {
       scrubbingContainer: 'plyr__preview-scrubbing',
       scrubbingContainerShown: 'plyr__preview-scrubbing--is-shown',
     },
+    markers: {
+      points: 'plyr__marker__points',
+      tip: 'plyr__marker__tip',
+    },
   },
 
   // Embed attributes
@@ -441,6 +445,12 @@ const defaults = {
     customControls: true,
     noCookie: false, // Whether to use an alternative version of YouTube without cookies
   },
+
+  // markers
+  markers: {
+    enabled: false,
+    points: [],
+  },
 };
 
 export default defaults;