fix intro sometimes not being wrapped in a paragraph

Author: jasonvarga

resources/views/partials/header.antlers.html

@@ -5,6 +5,6 @@ <h1 class="{{ title | length > 36 ?= 'text-5xl'}}">{{ title }}</h1>
         {{ partial:pro-badge }}
         {{ partial:experimental }}
     </div>
-    {{ intro ?? overview | markdown }}
+    {{ (intro ?? overview) | markdown }}
     {{ partial:toc hide="{hide_toc} ?? false"}}
 </header>