To avoid scope ambiguity, the default slot should also use ＜template＞ syntax when there are other na

<base-layout>
  <template v-slot:header> // slot="" 已经废弃 。！！！！
    <h1>Here might be a page title</h1>
  </template>

  <p>A paragraph for the main content.</p>
  <p>And another one.</p>

  <template v-slot:footer>
    <p>Here's some contact info</p>
  </template>
</base-layout>

<div class="container">
  <header>
    <slot name="header"></slot> // 当有多个slot 并且name 时 上面的就要写多个tempelte 了
  </header>
  <main>
    <slot></slot>
  </main>
  <footer>
    <slot name="footer"></slot>
  </footer>
</div>