add info labels to wrapping demo

Author: dmackdev

examples/demo/src/apps/wrapping.rs

@@ -34,6 +34,8 @@ impl Show for WrappingExample {
 
     fn show(&mut self, ui: &mut Ui) {
         ui.hyperlink_to("Source", "https://github.com/dmackdev/egui_json_tree/blob/master/examples/demo/src/apps/wrapping.rs");
+        ui.label("Use the controls below to configure the text wrapping options for primitive JSON values within the visualisation.");
+        ui.label("Text is truncated when it cannot fit in the specified width and number of rows.");
         ui.add_space(10.0);
 
         self.show_max_rows_controls(ui);