docs(render-function#template-refs): Make useTemplateRef the default example

[sofuxro]

Description of Problem

In guide/render-function the Template Refs uses the old way of template ref and only below the new (3.5) useTemplateRef. Everywhere in the docs 3.5 is the default with a fallback Accessing the Refs

Proposed Solution

• Made useTemplateRef default example
• Hid the other one in a collapsable pre-3.5 version
• Fixed an example issue in the useTemplateRef version <div ref="divEl"> -> <div ref="my-div">

Additional Information

[netlify]

✅ Deploy Preview for vuejs ready!

Name	Link
🔨 Latest commit	2ecf5c9
🔍 Latest deploy log	https://app.netlify.com/sites/vuejs/deploys/67d5e1fac9014900085721f4
😎 Deploy Preview	https://deploy-preview-3197--vuejs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.