docs: fix definition actions

Author: datamweb

docs/quickstart.md

@@ -110,7 +110,7 @@ Turned off by default, Shield's Email-based 2FA can be enabled by specifying the
 
 ```php
 public array $actions = [
-    'login'    => \CodeIgniter\Shield\Authentication\Actions\Email2FA,
+    'login'    => 'CodeIgniter\Shield\Authentication\Actions\Email2FA',
     'register' => null,
 ];
 ```
@@ -122,7 +122,7 @@ By default, once a user registers they have an active account that can be used.
 ```php
 public array $actions = [
     'login'    => null,
-    'register' => \CodeIgniter\Shield\Authentication\Actions\EmailActivator,
+    'register' => 'CodeIgniter\Shield\Authentication\Actions\EmailActivator',
 ];
 ```