docs: improve comments in Validation

Author: kenjis

system/Validation/Validation.php

@@ -462,14 +462,14 @@ public function withRequest(RequestInterface $request): ValidationInterface
     }
 
     /**
-     * Sets an individual rule and custom error messages for a single field.
+     * Sets (or adds) an individual rule and custom error messages for a single
+     * field.
      *
      * The custom error message should be just the messages that apply to
      * this field, like so:
-     *
      *    [
-     *        'rule' => 'message',
-     *        'rule' => 'message',
+     *        'rule1' => 'message1',
+     *        'rule2' => 'message2',
      *    ]
      *
      * @param array|string $rules
@@ -502,21 +502,21 @@ public function setRule(string $field, ?string $label, $rules, array $errors = [
 
     /**
      * Stores the rules that should be used to validate the items.
-     * Rules should be an array formatted like:
      *
+     * Rules should be an array formatted like:
      *    [
      *        'field' => 'rule1|rule2'
      *    ]
      *
      * The $errors array should be formatted like:
      *    [
      *        'field' => [
-     *            'rule' => 'message',
-     *            'rule' => 'message
+     *            'rule1' => 'message1',
+     *            'rule2' => 'message2',
      *        ],
      *    ]
      *
-     * @param array $errors // An array of custom error messages
+     * @param array $errors An array of custom error messages
      */
     public function setRules(array $rules, array $errors = []): ValidationInterface
     {