Update readme.md

BasicPrimitives · web-flow · commit 70bfb9832f0c · 2019-05-17T14:39:58.000-04:00
diff --git a/readme.md b/readme.md
@@ -7,6 +7,7 @@ Diagrams work in all major modern browsers Internet Explorer, Chrome, Firefox, S
 
 ## Supported Diagrams
 
+* Tree
 * Hierarchy Visualization
 * Organizational Chart
 * Multi-parent hierarchical chart
