refactor: site.params.diagram -> site.Params.features.diagram.enable

BREAKING CHANGE

See #2601

wowchemy/layouts/partials/site_js.html

@@ -28,7 +28,7 @@
         {{ printf "<script src=\"%s\" integrity=\"%s\" crossorigin=\"anonymous\"></script>" (printf $js.fancybox.url $js.fancybox.version) $js.fancybox.sri | safeHTML }}
       {{ end }}
 
-      {{ if or .Params.diagram site.Params.diagram }}
+      {{ if or .Params.diagram site.Params.features.diagram.enable }}
         {{ printf "<script src=\"%s\" integrity=\"%s\" crossorigin=\"anonymous\" title=\"mermaid\"></script>" (printf $js.mermaid.url $js.mermaid.version) $js.mermaid.sri | safeHTML }}
       {{ end }}