improved extensions readme

README.md

@@ -1,7 +1,33 @@
 SwiftMailer Extension for Yii 2
 ===============================
 
-This extension provides a `SwiftMailer` mail solution 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
+------------
+
+The preferred way to install this extension is through [composer](http://getcomposer.org/download/).
+
+Either run
+
+```
+php composer.phar require --prefer-dist yiisoft/yii2-swiftmailer
+```
+
+or add
+
+```json
+"yiisoft/yii2-swiftmailer": "~2.0.0"
+```
+
+to the require section of your composer.json.
+
+Usage
+-----
 
 To use this extension,  simply add the following code in your application configuration:
 
@@ -28,22 +54,3 @@ Yii::$app->mailer->compose('contact/html')
 
 For further instructions refer to the related section in the Yii Definitive Guide.
 
-
-Installation
-------------
-
-The preferred way to install this extension is through [composer](http://getcomposer.org/download/).
-
-Either run
-
-```
-php composer.phar require --prefer-dist yiisoft/yii2-swiftmailer "*"
-```
-
-or add
-
-```json
-"yiisoft/yii2-swiftmailer": "*"
-```
-
-to the require section of your composer.json.