add extended footer text (only english so far)

i18n/en.yaml

@@ -0,0 +1,2 @@
+footer:
+  running_on: "This website is served on an {{ .OS }} server with {{ .Webserver }}"

layouts/partials/extend-footer.html

@@ -0,0 +1,8 @@
+<div>
+    {{ $os := printf `<a class="hover:underline hover:decoration-primary-400 hover:text-primary-500" href="https://www.openbsd.org/" target="_blank" rel="noopener noreferrer">OpenBSD</a>` }}
+    {{ $webserver := printf `<a class="hover:underline hover:decoration-primary-400 hover:text-primary-500" href="https://httpd.apache.org/" target="_blank" rel="noopener noreferrer">Apache httpd</a>` }}
+    <p class="text-xs text-neutral-500 dark:text-neutral-400">
+    {{ i18n "footer.running_on" (dict "OS" $os "Webserver" $webserver) | safeHTML }}
+    </p>
+</div>
+