Use action link for ‘Add a new session’ link

Author: paulrobertlloyd

app/views/session/list.njk

@@ -14,10 +14,9 @@
     title: __("session.list.title")
   }) }}
 
-  {{ button({
+  {{ actionLink({
     text: __("session.new.label"),
-    href: "/sessions/new",
-    variant: "secondary"
+    href: "/sessions/new"
   }) }}
 
   <div class="nhsuk-grid-row">