[10.x] Fix return type of prefixedResource & prefixedResource (#47445)

* fix return type of `prefixedResource` & `prefixedResource`

* use FQN in docblocks

Author: milwad-dev

src/Illuminate/Routing/ResourceRegistrar.php

@@ -179,7 +179,7 @@ public function singleton($name, $controller, array $options = [])
      * @param  string  $name
      * @param  string  $controller
      * @param  array  $options
-     * @return void
+     * @return \Illuminate\Routing\Router
      */
     protected function prefixedResource($name, $controller, array $options)
     {
@@ -201,7 +201,7 @@ protected function prefixedResource($name, $controller, array $options)
      * @param  string  $name
      * @param  string  $controller
      * @param  array  $options
-     * @return void
+     * @return \Illuminate\Routing\Router
      */
     protected function prefixedSingleton($name, $controller, array $options)
     {