Merge pull request #5 from tyx/patch-1

Fix markup for official website link

Author: mnapoli

Diff for: README.md

@@ -4,7 +4,7 @@
 
 This library provides integration for PHP-DI v4 with Symfony 2.
 
-[PHP-DI](php-di.org) is a Dependency Injection Container for PHP.
+[PHP-DI](http://php-di.org) is a Dependency Injection Container for PHP.
 
 This library is compatible only with **PHP-DI 4.0** and above.