title: render() function to return default <slot /> in Vue 3
body: <p>A real simple question. I'm wondering, I have the following template:</p>
  <pre><code>&lt;template&gt;
    &lt;slot&gt;&lt;/slot&gt;
  &lt;/template&gt;
  </code></pre>
  <p>within a <code>ProviderComponent.vue</code>.</p>
  <p>I'm wondering if there is a way to use a render function to replace the use of <code>&lt;template&gt;</code> and <code>&lt;slot&gt;</code> in this case in Vue 3?</p>
  <p>I can't seem to find anything in the docs or else where ... but I'm sure it is more than possible.</p>