refactor templates layout

@see https://gohugo.io/templates/new-templatesystem-overview/

layouts/_partials/util/render_recursive_list.html

@@ -0,0 +1,58 @@
+<!--
+    Recursively render an ordered or unordered list from a set of arbitrarily-
+    deeply-nested items.
+
+    @params sc  Site context
+    @params pc  Page context
+    @params items   Set of items to render a list from.
+    @params itemtype  Schema.org type to apply. Optional.
+    @params listType    "unordered" or "ordered". Default "unordered".
+-->
+
+<!-- Validation -->
+
+{{- if not .sc.Site.Data.itemtypes -}}
+  {{- errorf "Can't access site context in partial (%q)" .pc.File.Path -}}
+{{- end -}}
+
+{{- if not .items -}}
+  {{- warnf "No items passed to list partial (%q)" .pc.File.Path -}}
+{{- end -}}
+
+{{- if ( and .itemtype ( not ( in .sc.Site.Data.itemtypes .itemtype ) ) ) -}}
+  {{- erroridf "invalid-itemtype" "Invalid Schema.org type value %q (%q)" .itemtype .pc.File.Path -}}
+{{- end -}}
+
+{{- if ( and .listType ( not ( in ( slice "unordered" "ordered" ) .listType ) ) ) -}}
+  {{- erroridf "invalid-listType" "Invalid list type value %q (%q)" .listType .pc.File.Path -}}
+{{- end -}}
+
+<!-- Default Assignment -->
+
+{{- $itemtype := default "" .itemtype -}}
+{{- $listType := default "unordered" .listType -}}
+
+<!-- Rendering -->
+
+{{- if ( eq $listType "unordered" ) -}}
+<ul>
+{{- else -}}
+<ol>
+{{- end -}}
+
+{{- range $k, $v := .items -}}
+  {{- if not ( isset $v "redact" ) -}}
+    <li itemscope itemtype="https://schema.org/Place">
+        {{- $k -}}
+        {{- if ( not ( isset $v "lat" ) ) -}}
+            {{- partial "util/render_recursive_list.html" ( dict "sc" $.sc "pc" $.pc "items" $v "itemtype" $itemtype "listType" $listType ) -}}
+        {{- end -}}
+    </li>
+  {{- end -}}
+{{- end -}}
+
+{{- if ( eq $listType "unordered" ) -}}
+</ul>
+{{- else -}}
+</ol>
+{{- end -}}