youtube embed playlist may also accept current video id

docs/.vitepress/theme/components/YouTube.vue

@@ -5,8 +5,8 @@
       width="100%"
       height="100%"
       :src="
-        'https://www.youtube.com/embed/' +
-        ($props.list ? `videoseries?list=${$props.list}` : $props.id)
+        `https://www.youtube.com/embed/${$props.id || 'videoseries'}` +
+        ($props.list ? `?list=${$props.list}` : '')
       "
       :title="$props.title"
       frameborder="0"