Update README.md

SweathaBharathi · web-flow · commit 73b617960487 · 2025-09-19T21:02:56.000+05:30
diff --git a/README.md b/README.md
@@ -12,3 +12,5 @@ int checkedCount = treeView1.CheckedNodes.Count;
 Dim checkedCount As Integer = treeView1.CheckedNodes.Count
 ```
 ![count of checked nodes](output.png)
+
+Take a moment to peruse the [WinForms TreeViewAdv - CheckBox](https://help.syncfusion.com/windowsforms/treeview/getting-started#checkbox) documentation, to learn more about checkbox with examples.
