feat: refine JSON-LD schema for posts and pages

- Updated `@type` logic to differentiate between `WebPage` and `CollectionPage`.
- Enhanced `BlogPosting` with `description`, `keywords`, and enriched `image` metadata.
- Improved logic for linking `mainEntity` to the associated article.

Author: denmette

themes/custom/layouts/partials/schema-jsonld.html

@@ -162,8 +162,13 @@
 {{- $pageURL := .Permalink -}}
 {{- $webpageId := printf "%s#webpage" $pageURL -}}
 {{- $webpageName := .Title | default $siteTitle -}}
+{{- $isPostList := or .IsHome (and (eq .Kind "section") (eq .Section "posts")) -}}
+{{- $webpageType := "WebPage" -}}
+{{- if $isPostList -}}
+  {{- $webpageType = "CollectionPage" -}}
+{{- end -}}
 {{- $webpageNode := dict
-  "@type" "WebPage"
+  "@type" $webpageType
   "@id" $webpageId
   "url" $pageURL
   "name" $webpageName
@@ -173,7 +178,6 @@
   {{- $webpageNode = merge $webpageNode (dict "inLanguage" $languageCode) -}}
 {{- end -}}
 
-{{- $isPostList := or .IsHome (and (eq .Kind "section") (eq .Section "posts")) -}}
 {{- if $isPostList -}}
   {{- $pageSize := 5 -}}
   {{- $posts := where .Site.RegularPages "Section" "posts" -}}
@@ -200,8 +204,6 @@
   {{- end -}}
 {{- end -}}
 
-{{- $nodes = $nodes | append $webpageNode -}}
-
 {{- if and .IsPage (eq .Section "posts") -}}
   {{- $imageURL := "" -}}
   {{- with .Params.cover.image -}}
@@ -226,18 +228,36 @@
     "isPartOf" (dict "@id" $blogId)
     "publisher" (dict "@id" $orgId)
   -}}
+  {{- $postDescription := .Params.description | default .Summary -}}
+  {{- if $postDescription -}}
+    {{- $blogPosting = merge $blogPosting (dict "description" ($postDescription | plainify | htmlUnescape)) -}}
+  {{- end -}}
+  {{- with .Params.tags -}}
+    {{- if gt (len .) 0 -}}
+      {{- $blogPosting = merge $blogPosting (dict "keywords" .) -}}
+    {{- end -}}
+  {{- end -}}
   {{- if $personName -}}
     {{- $blogPosting = merge $blogPosting (dict "author" (dict "@id" $personId)) -}}
   {{- end -}}
   {{- if $hasModified -}}
     {{- $blogPosting = merge $blogPosting (dict "dateModified" (.Lastmod.Format "2006-01-02T15:04:05Z07:00")) -}}
   {{- end -}}
   {{- if $imageURL -}}
-    {{- $blogPosting = merge $blogPosting (dict "image" $imageURL) -}}
+    {{- $imageObject := dict "@type" "ImageObject" "url" $imageURL -}}
+    {{- with .Params.cover.image -}}
+      {{- with $.Resources.GetMatch . -}}
+        {{- $imageObject = merge $imageObject (dict "width" .Width "height" .Height) -}}
+      {{- end -}}
+    {{- end -}}
+    {{- $blogPosting = merge $blogPosting (dict "image" $imageObject) -}}
   {{- end -}}
+  {{- $webpageNode = merge $webpageNode (dict "mainEntity" (dict "@id" (printf "%s#article" .Permalink))) -}}
   {{- $nodes = $nodes | append $blogPosting -}}
 {{- end -}}
 
+{{- $nodes = $nodes | append $webpageNode -}}
+
 {{- $graph := dict
   "@context" "https://schema.org"
   "@graph" $nodes