Added a validation link to the person page, clickable

person/templates/person/certificate.html

@@ -88,6 +88,14 @@ body:before {
   font-size: 24px;
   font-weight: bold;
 }
+#cert-debian-url a {
+  color: black;
+  text-decoration: none;
+}
+#cert-debian-url a:hover {
+  color: blue;
+  text-decoration: underline;
+}
 #cert-signature {
   display: grid;
   flex-grow: 2;
@@ -192,7 +200,7 @@ p {
 </div>
 
 <div id="cert-debian-url" class="textblock">
-  {{check_url}}
+  <a href="{{check_url}}">{{check_url}}</a>
 </div>
 
 <div id="cert-signature" class="textblock">