Add surface to 404 page

Signed-off-by: Alan Fernandes <alan@cipher.host>

Author: Rayuaz

static/templates/404.html

@@ -37,6 +37,10 @@
 
     <main role="main" id="main" class="notFound__main">
       <h1 class="notFound__title">404 <span>Not Found</span></h1>
+      <div class="notFound__help uSurface">
+        <p class="notFound__text">
+          The package or page <code>{{.Path}}</code> could not be found.
+        </p>
         <a class="notFound__link a" href="/">Return to homepage</a>
       </div>
     </main>