Fix discussion error

views/post.pug

@@ -25,7 +25,7 @@ block content
             if ($post["type"] == "blog")
                 a(href="/") blog
             if ($post["type"] == "note")
-                a(href="notes") notes
+                a(href="/notes") notes
             |  > !{$post['slug']}
             
     main
@@ -40,7 +40,7 @@ block content
             .longform__content.e-content
                 | !{$post['content']}
         
-        if (array_key_exists('discussion', $post))
+        if (array_key_exists('discussion', $post) && isset($post['discussion']))
             .discussion.subsection
                 h2 Join the discussion
                 each $item in $post["discussion"]