Update README.md

Author: Igor Chepurnoy

README.md

@@ -1,4 +1,37 @@
-yii2-validators
-===============
+Yii2 validators
+===============================================
+
+Installation
+------------
+
+The preferred way to install this extension is through [composer](http://getcomposer.org/download/).
+
+Either run
+
+```
+php composer.phar require --prefer-dist yii2mod/yii2-validators "*"
+```
+
+or add
+
+```
+"yii2mod/yii2-validators": "*"
+```
+
+to the require section of your `composer.json` file.
+
+Usage
+-----
+1. ECCValidator
+```php
+    /**
+     * @return array the validation rules.
+     */
+    public function rules()
+    {
+        return [
+            [['creditCard'], \yii2mod\validators\ECCValidator::className()],
+        ];
+    }
+```
 
-* ECCValidator