docs(carousel): improve thumbnails example

Resolves #4032

docs/app/components/content/examples/carousel/CarouselThumbnailsExample.vue

@@ -17,9 +17,12 @@ function onClickPrev() {
 function onClickNext() {
   activeIndex.value++
 }
-
 function onSelect(index: number) {
   activeIndex.value = index
+}
+
+function select(index: number) {
+  activeIndex.value = index
 
   carousel.value?.emblaApi?.scrollTo(index)
 }
@@ -35,6 +38,7 @@ function onSelect(index: number) {
       :prev="{ onClick: onClickPrev }"
       :next="{ onClick: onClickNext }"
       class="w-full max-w-xs mx-auto"
+      @select="onSelect"
     >
       <img :src="item" width="320" height="320" class="rounded-lg">
     </UCarousel>
@@ -45,7 +49,7 @@ function onSelect(index: number) {
         :key="index"
         class="size-11 opacity-25 hover:opacity-100 transition-opacity"
         :class="{ 'opacity-100': activeIndex === index }"
-        @click="onSelect(index)"
+        @click="select(index)"
       >
         <img :src="item" width="44" height="44" class="rounded-lg">
       </div>