feat(CommandPalette): handle children in items (#4226)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

docs/app/components/content/examples/command-palette/CommandPaletteCustomSlotExample.vue

@@ -83,7 +83,7 @@ const groups = [
     </template>
 
     <template #billing-label="{ item }">
-      {{ item.label }}
+      <span class="font-medium text-primary">{{ item.label }}</span>
 
       <UBadge variant="subtle" size="sm">
         50% off

docs/app/components/content/examples/command-palette/CommandPaletteItemsChildrenExample.vue

@@ -0,0 +1,119 @@
+<script setup lang="ts">
+const toast = useToast()
+
+const groups = [{
+  id: 'actions',
+  label: 'Actions',
+  items: [{
+    label: 'Create new',
+    icon: 'i-lucide-plus',
+    children: [{
+      label: 'New file',
+      icon: 'i-lucide-file-plus',
+      suffix: 'Create a new file in the current directory',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'New file created!' })
+      },
+      kbds: ['meta', 'N']
+    }, {
+      label: 'New folder',
+      icon: 'i-lucide-folder-plus',
+      suffix: 'Create a new folder in the current directory',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'New folder created!' })
+      },
+      kbds: ['meta', 'F']
+    }, {
+      label: 'New project',
+      icon: 'i-lucide-folder-git',
+      suffix: 'Create a new project from a template',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'New project created!' })
+      },
+      kbds: ['meta', 'P']
+    }]
+  }, {
+    label: 'Share',
+    icon: 'i-lucide-share',
+    children: [{
+      label: 'Copy link',
+      icon: 'i-lucide-link',
+      suffix: 'Copy a link to the current item',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'Link copied to clipboard!' })
+      },
+      kbds: ['meta', 'L']
+    }, {
+      label: 'Share via email',
+      icon: 'i-lucide-mail',
+      suffix: 'Share the current item via email',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'Share via email dialog opened!' })
+      }
+    }, {
+      label: 'Share on social',
+      icon: 'i-lucide-share-2',
+      suffix: 'Share the current item on social media',
+      children: [{
+        label: 'Twitter',
+        icon: 'i-simple-icons-twitter',
+        onSelect(e: Event) {
+          e.preventDefault()
+          toast.add({ title: 'Shared on Twitter!' })
+        }
+      }, {
+        label: 'LinkedIn',
+        icon: 'i-simple-icons-linkedin',
+        onSelect(e: Event) {
+          e.preventDefault()
+          toast.add({ title: 'Shared on LinkedIn!' })
+        }
+      }, {
+        label: 'Facebook',
+        icon: 'i-simple-icons-facebook',
+        onSelect(e: Event) {
+          e.preventDefault()
+          toast.add({ title: 'Shared on Facebook!' })
+        }
+      }]
+    }]
+  }, {
+    label: 'Settings',
+    icon: 'i-lucide-settings',
+    children: [{
+      label: 'General',
+      icon: 'i-lucide-sliders',
+      suffix: 'Configure general settings',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'General settings opened!' })
+      }
+    }, {
+      label: 'Appearance',
+      icon: 'i-lucide-palette',
+      suffix: 'Customize the appearance',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'Appearance settings opened!' })
+      }
+    }, {
+      label: 'Security',
+      icon: 'i-lucide-shield',
+      suffix: 'Manage security settings',
+      onSelect(e: Event) {
+        e.preventDefault()
+        toast.add({ title: 'Security settings opened!' })
+      }
+    }]
+  }]
+}]
+</script>
+
+<template>
+  <UCommandPalette :groups="groups" class="flex-1" />
+</template>