Updated readme

README.md

@@ -3,8 +3,6 @@ SwiftMailer Extension for Yii 2
 
 This extension provides a [SwiftMailer](http://swiftmailer.org/) mail solution for Yii 2.
 
-This repository is a git submodule of <https://github.com/yiisoft/yii2>.
-Please submit issue reports and pull requests to the main repository.
 For license information check the [LICENSE](LICENSE.md)-file.
 
 Installation
@@ -52,5 +50,5 @@ Yii::$app->mailer->compose('contact/html')
      ->send();
 ```
 
-For further instructions refer to the related section in the Yii Definitive Guide.
+For further instructions refer to the [related section in the Yii Definitive Guide](http://www.yiiframework.com/doc-2.0/guide-tutorial-mailing.html).