🌐 Localize reply-by-email subject

Use a new article.reply_to i18n key for the generated reply-by-email subject instead of the hardcoded English prefix.

Add the missing translations across i18n files and keep the existing English subject as fallback.

Fixes #2936

layouts/_default/single.html

@@ -51,12 +51,13 @@
           {{ $defaultReplyByEmail := site.Params.replyByEmail }}
           {{ $replyByEmail := default $defaultReplyByEmail .Params.replyByEmail }}
           {{ if $replyByEmail }}
+            {{ $replySubject := i18n "article.reply_to" (dict "Title" .Title) | default (printf "Reply to %s" .Title) }}
             <strong class="block mt-8">
               <a
                 class="email-link m-1 rounded bg-neutral-300 p-1.5 text-neutral-700 hover:bg-primary-500 hover:text-neutral dark:bg-neutral-700 dark:text-neutral-300 dark:hover:bg-primary-400 dark:hover:text-neutral-800"
                 href="#"
                 data-email="{{ site.Params.Author.email | base64Encode }}"
-                data-subject="{{ replace (printf "Reply to %s" .Title) "\"" "'" }}">
+                data-subject="{{ replace $replySubject "\"" "'" }}">
                 {{ i18n "article.reply_by_email" | default "Reply by Email" }}
               </a>
               <noscript>