Fix breadcrumb structured data (missing itemListElement)

- Remove invalid RDFa BreadcrumbList/ListItem markup from nav menu
  (was missing required itemListElement, and mismarked site nav as
  a breadcrumb trail)
- Add proper JSON-LD BreadcrumbList in structured_data.html built
  from each page's actual ancestor chain (Home > Section > Page)
  with position/name/item on every entry

Author: whiletruelearn

layouts/_default/baseof.html

@@ -48,9 +48,9 @@
               <a href="{{ .Site.BaseURL }}" class="no-style {{ with .Site.Params.TitleCutting }}site-name{{ end }}">{{ .Site.Title }}</a>:~# 
               {{ range $index, $element := split $url "/" }}{{ $.Scratch.Add "path" $element }}{{ if ne $element "" }}<a href='{{ $.Scratch.Get "path" | absURL }}'>{{ . }}</a>/{{ $.Scratch.Add "path" "/" }}{{ end }}{{ end }}</div></header>
           <nav class="terminal-menu">
-            <ul vocab="https://schema.org/" typeof="BreadcrumbList">
+            <ul>
                 {{ range .Site.Params.navlinks }}
-                <li><a href="{{ absURL .url }}" typeof="ListItem">{{ .name }}</a></li>
+                <li><a href="{{ absURL .url }}">{{ .name }}</a></li>
                 {{ end }}
                 <li>
                   <button type="button" id="theme-toggle" class="theme-toggle" aria-label="Toggle dark mode" title="Toggle dark mode">

themes/hugo-theme-console/layouts/_default/baseof.html

@@ -48,9 +48,9 @@
               <a href="{{ .Site.BaseURL }}" class="no-style {{ with .Site.Params.TitleCutting }}site-name{{ end }}">{{ .Site.Title }}</a>:~# 
               {{ range $index, $element := split $url "/" }}{{ $.Scratch.Add "path" $element }}{{ if ne $element "" }}<a href='{{ $.Scratch.Get "path" | absURL }}'>{{ . }}</a>/{{ $.Scratch.Add "path" "/" }}{{ end }}{{ end }}</div></header>
           <nav class="terminal-menu">
-            <ul vocab="https://schema.org/" typeof="BreadcrumbList">
+            <ul>
                 {{ range .Site.Params.navlinks }}
-                <li><a href="{{ absURL .url }}" typeof="ListItem">{{ .name }}</a></li>
+                <li><a href="{{ absURL .url }}">{{ .name }}</a></li>
                 {{ end }}
             </ul>
           </nav>

themes/hugo-theme-console/layouts/partials/structured_data.html

@@ -24,3 +24,24 @@
 {{ $schema | jsonify (dict "indent" "  ") | safeJS }}
 </script>
 {{- end }}
+
+<!-- JSON-LD BreadcrumbList, emitted on every non-home page -->
+{{- if not .IsHome }}
+{{- $crumbs := slice . }}
+{{- $node := . }}
+{{- range $node.Ancestors }}
+  {{- $crumbs = $crumbs | append . }}
+{{- end }}
+{{- $crumbs = $crumbs | collections.Reverse }}
+{{- $items := slice }}
+{{- $pos := 1 }}
+{{- range $crumbs }}
+  {{- $name := cond .IsHome $.Site.Title .Title }}
+  {{- $items = $items | append (dict "@type" "ListItem" "position" $pos "name" $name "item" .Permalink) }}
+  {{- $pos = add $pos 1 }}
+{{- end }}
+{{- $breadcrumb := dict "@context" "https://schema.org" "@type" "BreadcrumbList" "itemListElement" $items }}
+<script type="application/ld+json">
+{{ $breadcrumb | jsonify (dict "indent" "  ") | safeJS }}
+</script>
+{{- end }}