Support postfix HTML in addition to prefix HTML for navbar items

See https://gohugo.io/variables/menus/

layouts/partials/navbar.html

@@ -56,6 +56,7 @@
           <a href="{{ .URL | relLangURL }}"{{ if $.IsHome }} data-target="{{ .URL }}"{{ end }}>
             {{ .Pre }}
             <span>{{ .Name }}</span>
+            {{ .Post }}
           </a>
         </li>