Update ion-icons from 4.5 to latest version

[adriguerra]

It would be great to update ion-icons to the latest version (7.1.0 at the time of this post). Currently, the template uses version 4.5.0, but some social icons (like Medium) aren't available.

I first tried changing the reference to the version in site/_includes/head.html to 7.1.0 but that didn't work.
<link href="https://unpkg.com/[email protected]/dist/css/ionicons.min.css" rel="stylesheet">

I also tried adding:

<script type="module" src="https://unpkg.com/[email protected]/dist/ionicons/ionicons.esm.js"></script>
<script nomodule src="https://unpkg.com/[email protected]/dist/ionicons/ionicons.js"></script>

to site/_layouts/default.html as described here but that didn't work either.

I presume this would help, but I'm not sure how to proceed.