docs: Change wrong info about controller default scope (#885)

* Revert "Update scope.adoc (#509)"

This reverts commit 9b3884d.

* docs: Add note about controller scope

src/en/ref/Controllers/scope.adoc

@@ -26,11 +26,13 @@ class BookController {
 === Description
 
 
-Unless specified by the `grails.controllers.defaultScope` property in `application.yml`, controllers by default are "singleton" scoped which means that only one instance of the controller exists.
-This behaviour can be set for an individual controller by specifying a `scope` attribute with one of the following values:
+Unless specified by the `grails.controllers.defaultScope` property in `application.yml`, controllers are by default "prototype"-scoped which means that a new controller will be created for each request.
+The scope can be set for an individual controller by specifying a static `scope` attribute with one of the following values:
 
-* `singleton` (default) - Only one instance of the controller ever exists (recommended for actions as methods)
-* `prototype` - A new controller will be created for each request (recommended for actions as Closure properties)
+* `prototype` (default) - A new controller will be created for each request (recommended for actions as Closure properties)
 * `session` - One controller is created for the scope of a user session
+* `singleton` - Only one instance of the controller ever exists (recommended for actions as methods)
+
+NOTE: Newly created applications have the `grails.controllers.defaultScope` config property set to a value of "singleton" in `application.yml`.
 
 See link:{guidePath}/theWebLayer.html#controllersAndScopes[Controllers and Scopes] in the user guide for more information.