Update docs, add Editor script: Create Druid GUI Script, add simple using widgets example

example/druid.gui

@@ -4998,6 +4998,13 @@ nodes {
   parent: "container_resize/panel_content"
   template_node_child: true
 }
+nodes {
+  type: TYPE_TEMPLATE
+  id: "use_widgets"
+  parent: "container"
+  inherit_alpha: true
+  template: "/example/examples/container/use_widgets/use_widgets.gui"
+}
 nodes {
   position {
     x: -20.0