feat(Carousel): expose methods to allow autoplay

Resolves #1300

docs/components/content/examples/CarouselExampleAutoplay.vue

@@ -0,0 +1,37 @@
+<script setup lang="ts">
+const items = [
+  'https://picsum.photos/1920/1080?random=1',
+  'https://picsum.photos/1920/1080?random=2',
+  'https://picsum.photos/1920/1080?random=3',
+  'https://picsum.photos/1920/1080?random=4',
+  'https://picsum.photos/1920/1080?random=5',
+  'https://picsum.photos/1920/1080?random=6'
+]
+
+const carouselRef = ref()
+
+onMounted(() => {
+  setInterval(() => {
+    if (!carouselRef.value) return
+
+    if (carouselRef.value.page === carouselRef.value.pages) {
+      return carouselRef.value.select(0)
+    }
+
+    carouselRef.value.next()
+  }, 3000)
+})
+</script>
+
+<template>
+  <UCarousel
+    ref="carouselRef"
+    v-slot="{ item }"
+    :items="items"
+    :ui="{ item: 'basis-full' }"
+    class="rounded-lg overflow-hidden"
+    indicators
+  >
+    <img :src="item" class="w-full" draggable="false">
+  </UCarousel>
+</template>