Started railroad diagrams

demos/index.html

@@ -7,7 +7,6 @@
     <link rel="icon" type="image/png" href="data:image/png;base64,iVBORw0KGgo=" />
     <style>
       div.mermaid {
-        /* font-family: 'trebuchet ms', verdana, arial; */
         font-family: 'Courier New', Courier, monospace !important;
       }
     </style>
@@ -78,6 +77,9 @@
       <li>
         <h2><a href="./sankey.html">Sankey</a></h2>
       </li>
+      <li>
+        <h2><a href="./railroad.html">Railroad</a></h2>
+      </li>
     </ul>
   </body>
 </html>