Fixed the PHP-DI entry

- the name is PHP-DI (instead of PHP DI)
- updated the URL
- updated the description (annotations have become a secondary feature and are encompassed by "autowiring")

README.md

 * [Pimple](http://pimple.sensiolabs.org/) - A tiny dependency injection container.
 * [Auryn](https://github.com/rdlowrey/Auryn) - Another dependency injection container.
 * [Container](https://github.com/thephpleague/container) - Another flexible dependency injection container.
-* [PHP DI](http://mnapoli.github.com/PHP-DI/) - A dependency injection implementation using annotations.
+* [PHP-DI](http://php-di.org/) - A dependency injection container supporting autowiring and PHP configuration.
 * [Acclimate](https://github.com/jeremeamia/acclimate) - A common interface to dependency injection containers and service locators.
 * [Symfony DI](https://github.com/symfony/DependencyInjection) - A dependency injection container component (SF2).