feat(Timeline): new component (#4215)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>
Co-authored-by: Jakub <jakub.michalek@freelo.io>

docs/app/components/content/examples/timeline/TimelineSlotsExample.vue

@@ -0,0 +1,60 @@
+<script lang="ts" setup>
+import type { TimelineItem } from '@nuxt/ui'
+import { useTimeAgo } from '@vueuse/core'
+
+const items = [{
+  username: 'J-Michalek',
+  date: '2025-05-24T14:58:55Z',
+  action: 'opened this',
+  avatar: {
+    src: 'https://github.com/J-Michalek.png'
+  }
+}, {
+  username: 'J-Michalek',
+  date: '2025-05-26T19:30:14+02:00',
+  action: 'marked this pull request as ready for review',
+  icon: 'i-lucide-check-circle'
+}, {
+  username: 'benjamincanac',
+  date: '2025-05-27T11:01:20Z',
+  action: 'commented on this',
+  description: 'I\'ve made a few changes, let me know what you think! Basically I updated the design, removed unnecessary divs, used Avatar component for the indicator since it supports icon already.',
+  avatar: {
+    src: 'https://github.com/benjamincanac.png'
+  }
+}, {
+  username: 'J-Michalek',
+  date: '2025-05-27T11:01:20Z',
+  action: 'commented on this',
+  description: 'Looks great! Good job on cleaning it up.',
+  avatar: {
+    src: 'https://github.com/J-Michalek.png'
+  }
+}, {
+  username: 'benjamincanac',
+  date: '2025-05-27T11:01:20Z',
+  action: 'merged this',
+  icon: 'i-lucide-git-merge'
+}] satisfies TimelineItem[]
+</script>
+
+<template>
+  <UTimeline
+    :items="items"
+    size="xs"
+    class="w-96"
+    :ui="{
+      date: 'float-end ms-1',
+      description: 'px-3 py-2 ring ring-default mt-2 rounded-md text-default'
+    }"
+  >
+    <template #title="{ item }">
+      <span>{{ item.username }}</span>
+      <span class="font-normal text-muted">&nbsp;{{ item.action }}</span>
+    </template>
+
+    <template #date="{ item }">
+      {{ useTimeAgo(new Date(item.date)) }}
+    </template>
+  </UTimeline>
+</template>