add reset password events docs

docs/events/reset-password-events.md

@@ -0,0 +1,54 @@
+Reset Password Events
+=====================
+
+The following is the list of the reset password events and where they happen: 
+
+On Controllers
+--------------
+
+- **RecoveryController**
+    - **ResetPasswordEvent::EVENT_BEFORE_TOKEN_VALIDATE**: Occurs before a reset password token is validated
+    - **ResetPasswordEvent::EVENT_AFTER_RESET**: Occurs after the password has been reset
+    
+How to Work With Reset Password Events
+--------------------------------------
+
+This event is a bit more special than the others. When the token is about to be validated and the 
+`EVENT_BEFORE_TOKEN_VALIDATE` is raised, only contains an instance of `Da\User\Model\Token` model and is accessible via 
+`Da\Form\ResetPasswordEvent::getToken()` method. But after the token is successfully validated, then when the 
+`Event_AFTER_RESET` is triggered, you can also access a `Da\User\Form\RecoveryForm` instance via its 
+`Da\Form\ResetPasswordEvent::getToken()` method. 
+
+Check the following code as an example: 
+
+```php 
+<?php 
+// events.php file
+
+use Da\Controller\RecoveryController;
+use Da\Event\ResetPasswordEvent;
+use yii\base\Event;
+
+Event::on(
+    RecoveryController::class, 
+    ResetPasswordEvent::EVENT_BEFORE_TOKEN_VALIDATE, 
+    function (ResetPasswordEvent $event) {
+    
+        $token = $event->getToken(); // $token is a Da\User\Model\Token instance
+        $form = $event->getForm(); // form is NULL
+
+        // ... your logic here
+    });
+
+Event::on(
+    RecoveryController::class, 
+    ResetPasswordEvent::EVENT_AFTER_RESET, 
+    function (ResetPasswordEvent $event) {
+    
+        $token = $event->getToken(); // $token is a Da\User\Model\Token instance
+        $form = $event->getForm(); // form is a Da\User\Form\RecoveryForm instance with submitted data
+
+        // ... your logic here
+    });
+
+```

src/User/Event/ResetPasswordEvent.php

@@ -25,7 +25,7 @@ class ResetPasswordEvent extends Event
     protected $form;
     protected $token;
 
-    public function __construct(Token $token, RecoveryForm $form, array $config = [])
+    public function __construct(Token $token = null, RecoveryForm $form = null, array $config = [])
     {
         $this->form = $form;
         $this->token = $token;