added sequence numbers

src/mermaidAPI.js

@@ -153,7 +153,13 @@ const config = {
      * **useMaxWidth** - when this flag is set the height and width is set to 100% and is then scaling with the
      * available space if not the absolute space required is used
      */
-    useMaxWidth: true
+    useMaxWidth: true,
+
+    /**
+     * **showSequenceNumbers** - this will show the node numbers
+     */
+    showSequenceNumbers: false
+
   },
 
   /** ### gantt