SwiftMailer logo added

README.md

@@ -1,7 +1,12 @@
-SwiftMailer Extension for Yii 2
-===============================
-
-This extension provides a [SwiftMailer](http://swiftmailer.org/) mail solution for [Yii framework 2.0](http://www.yiiframework.com).
+<p align="center">
+    <a href="https://swiftmailer.symfony.com/" target="_blank" rel="external">
+        <img src="https://swiftmailer.symfony.com/images/logo.png" height="68px">
+    </a>
+    <h1 align="center">SwiftMailer Extension for Yii 2</h1>
+    <br>
+</p>
+
+This extension provides a [SwiftMailer](https://swiftmailer.symfony.com/) mail solution for [Yii framework 2.0](http://www.yiiframework.com).
 
 For license information check the [LICENSE](LICENSE.md)-file.