Added link to the wiki to the page navigation

src/_layouts/default.html

@@ -21,6 +21,7 @@
       <ul>
         <li><a href="{% link index.markdown %}">Home</a></li>
         <li><a href="{% link blog.markdown %}">Blog Posts</a></li>
+	<li><a href="https://wiki.bitgoblin.tech/">Wiki</a></li>
         <li><a href="{% link support.markdown %}">Support</a></li>
         <li><a href="{% link contact.markdown %}">Contact</a></li>
       </ul>