docs: fix vue example

examples/nuxt-example/components/ui/select/SelectLabel.vue

@@ -0,0 +1,13 @@
+<script setup lang="ts">
+import type { HTMLAttributes } from 'vue'
+import { SelectLabel, type SelectLabelProps } from 'radix-vue'
+import { cn } from '@/lib/utils'
+
+const props = defineProps<SelectLabelProps & { class?: HTMLAttributes['class'] }>()
+</script>
+
+<template>
+  <SelectLabel :class="cn('px-2 py-1.5 text-sm font-semibold', props.class)">
+    <slot />
+  </SelectLabel>
+</template>