docs: improve sample code

Author: kenjis

user_guide_src/source/general/configuration/007.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace CodeIgniter\Shield\Config;
+
 class Registrar
 {
     public static function Pager(): array

user_guide_src/source/general/configuration/008.php

@@ -2,6 +2,8 @@
 
 namespace Config;
 
+// ...
+
 class MyConfig extends BaseConfig
 {
     public static $registrars = [

user_guide_src/source/general/configuration/009.php

@@ -6,8 +6,8 @@
 
 class MySalesConfig extends BaseConfig
 {
-    public $target            = 100;
-    public $campaign          = 'Winter Wonderland';
+    public int $target        = 100;
+    public string $campaign   = 'Winter Wonderland';
     public static $registrars = [
         '\App\Models\RegionalSales',
     ];

user_guide_src/source/general/configuration/010.php

@@ -4,7 +4,7 @@
 
 class RegionalSales
 {
-    public static function MySalesConfig()
+    public static function MySalesConfig(): array
     {
         return [
             'target' => 45,