General fixes and additions

- Improve readability on larger and smaller screens
- Re-add page signing with a custom script (which is signed of course)
- Posts are now centered on large screens
- <code> now stops overflowing and receives a scrollbar
- The mobile page now stops to overflow

layout/post.html

@@ -1,7 +1,15 @@
-<div class="post">
-    <article>
-        <h1>{{ title }}</h1>
+<div class="horizontal-center">
+    <div class="post">
+        <article>
+            <h1>{{ title }}</h1>
 
-        {{ content }}
-    </article>
+            {{ content }}
+        
+            <br />
+
+            If you have any questions or comments, then feel free to send me an email
+            (Preferably with <a href="{{ email_gpg_url }}">GPG encryption</a> to
+            {{ email_user }} [weird "a" with a circle] {{ email_domain }}. 
+        </article>
+    </div>
 </div>