onec.me/themes/beautifulhugo/layouts/shortcodes/mermaid.html

<link href="{{"css/mermaid.css" | relURL}}" type="text/css" rel="stylesheet"/>
<script defer src="{{"js/mermaid.js" | relURL}}">
    mermaid.initialize({startOnLoad:true});
</script>
<div class="mermaid" align="{{ if .Get "align" }}{{ .Get "align" }}{{ else }}center{{ end }}" >
    {{ safeHTML .Inner  }}
</div>