Add last-modified section to bottom of docs pages

Author: nginx-jack

assets/css/f5-hugo.css

@@ -1648,4 +1648,8 @@ li.nav-item a.nav-link {
 .remove-bottom-radius {
   border-bottom-left-radius: 0;
   border-bottom-right-radius: 0;
+}
+
+.last-modified {
+  font-weight:300;
 }

layouts/_default/docs.html

@@ -21,8 +21,14 @@ <h1>{{ .Title }}</h1>
     {{ .Content }}
     {{ partial "version-list" . }}
   <hr>
+
+  {{ if .Page.Lastmod }}
+  <div class="last-modified">
+    Last modified {{ .Page.Lastmod.Format "January 2, 2006" }}
+  </div>
+  {{ end }}
+
     {{ partial "previous-next-links-in-section-with-title.html" . }}
-    
   </main>
   {{ if and (gt .WordCount 200 ) (.Params.toc) }}
     {{ if (add  (len (findRE "<h3" .Content)) (len (findRE "<h2" .Content))) }}
@@ -31,6 +37,7 @@ <h1>{{ .Title }}</h1>
       </div>
     {{ end }}
   {{ end }}
+
 </div>
 <!-- If there is a script defined in the page metadata, load it  -->
 {{if .Params.script}}