examples/hello: Also test password text input

examples/hello/app/windows/lvguitesting.rb

@@ -27,6 +27,20 @@ module GUI
         end
       end
 
+      add_textarea().tap do |ta|
+        ta.set_pwd_mode(true)
+        on_click = ->() do
+          puts "clicked"
+        end
+        ta.on_submit = ->(value) do
+          puts "submitted #{value.inspect}"
+          puts " -> get_text: #{ta.get_text().inspect}"
+        end
+        ta.on_modified = ->(value) do
+          puts "modified #{value.inspect}"
+        end
+      end
+
       # Add a toggle switch
       @switch = add_switch(
         "Toggle switch",