Add Cloudflare Web Analytics support

[Jinglue]

js snippet like

<!-- Cloudflare Web Analytics -->
<script defer
	src='https://static.cloudflareinsights.com/beacon.min.js'
	data-cf-beacon='{"token": "personal token here"}'>
</script>
<!-- End Cloudflare Web Analytics -->

docs here: https://developers.cloudflare.com/analytics/web-analytics/getting-started

[WingLim]

You can add custom script with footer/custom.html

Add partials/footer/custom.html to your site root directory layouts (Not theme layouts),
then add your script in custom.html.