add readme to dbal pkg.

pkg/dbal/README.md

@@ -0,0 +1,18 @@
+# Doctrine DBAL Transport
+
+[![Gitter](https://badges.gitter.im/php-enqueue/Lobby.svg)](https://gitter.im/php-enqueue/Lobby)
+[![Build Status](https://travis-ci.org/php-enqueue/dbal.png?branch=master)](https://travis-ci.org/php-enqueue/dbal)
+[![Total Downloads](https://poser.pugx.org/enqueue/dbal/d/total.png)](https://packagist.org/packages/enqueue/dbal)
+[![Latest Stable Version](https://poser.pugx.org/enqueue/dbal/version.png)](https://packagist.org/packages/enqueue/dbal)
+
+This is an implementation of PSR specification. It allows you to send and consume message through Doctrine DBAL library and SQL like database as broker.  
+
+## Resources
+
+* [Documentation](https://github.com/php-enqueue/enqueue-dev/blob/master/docs/index.md)
+* [Questions](https://gitter.im/php-enqueue/Lobby)
+* [Issue Tracker](https://github.com/php-enqueue/enqueue-dev/issues)
+
+## License
+
+It is released under the [MIT License](LICENSE).