Pre-process architecture docs as ERB for image tags

website/source/docs/internals/architecture.html.markdown.erb

@@ -69,7 +69,9 @@ allowing a client to make a request from a server.
 
 From a 10,000 foot altitude the architecture of Consul looks like this:
 
-![Consul Architecture](/images/consul-arch.png)
+<div class="center">
+  <%= link_to image_tag('consul-arch.png', alt: 'Consul Architecture'), image_path('consul-arch.png') %>
+</div>
 
 Lets break down this image and describe each piece. First of all we can see
 that there are two datacenters, one and two respectively. Consul has first