fix: prevent errors if show_related hasn't been added to params.toml

Fix 9e562fc076

layouts/partials/page_edit.html

@@ -1,4 +1,5 @@
-{{ if site.Params.edit_page }}{{/* Make `edit_page` optional in `params.toml` - prevent errors if it's removed. */}}
+{{/* This makes `edit_page` optional in `params.toml` and prevents errors if it's removed. */}}
+{{ if site.Params.edit_page }}
 {{ if site.Params.edit_page.repo_url | and (index site.Params.edit_page.editable .Type) | and (ne .Params.editable false) | or .Params.editable }}
 {{/* Get language subfolder for multilingual sites. */}}
 {{/* Limitations: the subfolder param, `<LANG>.contentDir`, is unexposed in the Hugo `site` API so we attempt to workaround this issue. */}}

layouts/partials/page_related.html

@@ -1,3 +1,5 @@
+{{/* This makes `show_related` optional in `params.toml` and prevents errors if it's removed. */}}
+{{ if site.Params.show_related }}
 {{ if (index site.Params.show_related .Type) | and (ne .Params.show_related false) | or .Params.show_related }}
   {{ $related := site.RegularPages.Related . | first 5 }}
   {{ with $related }}
@@ -11,3 +13,4 @@
   </div>
   {{ end }}
 {{ end }}
+{{ end }}