Started layout and rendering

demos/block.html

@@ -18,14 +18,18 @@
     <pre class="mermaid">
       block-beta
 
-      block TCP_IP["TCP/IP"]
     </pre>
-<!--
+    <!--
+      blockDiagram
+      
+      classDef background stroke-width:0;    
+
+      block(""):::background
         columns H
         ApplicationLayer("Application Layer")
         block
           columns H
-          UserInterface("User Interface (WPF, HTML5/CSS3, Swing)")
+          UserInterface("User Interface (WPF, HTML5/CSS3, Swing)"):3
         end
       end