docs: update docs

Author: kenjis

docs/concepts.md

@@ -29,7 +29,7 @@ is provided for you at `CodeIgniter\Shield\Models\UserModel`. You can change thi
 The only requirement is that your new class MUST extend the provided `UserModel`.
 
 ```php
-public $userProvider = 'CodeIgniter\Shield\Models\UserModel';
+public $userProvider = UserModel::class;
 ```
 
 ## User Identities
@@ -80,10 +80,10 @@ You can choose which validators are used in `Config\Auth::$passwordValidators`:
 
 ```php
 public $passwordValidators = [
-    'CodeIgniter\Shield\Authentication\Passwords\CompositionValidator',
-    'CodeIgniter\Shield\Authentication\Passwords\NothingPersonalValidator',
-    'CodeIgniter\Shield\Authentication\Passwords\DictionaryValidator',
-    //'CodeIgniter\Shield\Authentication\Passwords\PwnedValidator',
+    CompositionValidator::class,
+    NothingPersonalValidator::class,
+    DictionaryValidator::class,
+    // PwnedValidator::class,
 ];
 ```
 

docs/quickstart.md

@@ -113,7 +113,7 @@ By default, once a user registers they have an active account that can be used.
 
 ```php
 public array $actions = [
-    'register' => 'CodeIgniter\Shield\Authentication\Actions\EmailActivator',
+    'register' => \CodeIgniter\Shield\Authentication\Actions\EmailActivator::class,
     'login'    => null,
 ];
 ```
@@ -125,7 +125,7 @@ Turned off by default, Shield's Email-based 2FA can be enabled by specifying the
 ```php
 public array $actions = [
     'register' => null,
-    'login'    => 'CodeIgniter\Shield\Authentication\Actions\Email2FA',
+    'login'    => \CodeIgniter\Shield\Authentication\Actions\Email2FA::class,
 ];
 ```