Add Drupal integration to the README (#1639)

README.md

@@ -93,6 +93,7 @@ Bugs and feature request are tracked on [GitHub](https://github.com/Seldaek/mono
 - [Yii 2](http://www.yiiframework.com/) is usable with Monolog via the [yii2-monolog](https://github.com/merorafael/yii2-monolog) or [yii2-psr-log-target](https://github.com/samdark/yii2-psr-log-target) plugins.
 - [Hawkbit Micro Framework](https://github.com/HawkBitPhp/hawkbit) comes out of the box with Monolog.
 - [SilverStripe 4](https://www.silverstripe.org/) comes out of the box with Monolog.
+- [Drupal](https://www.drupal.org/) is usable with Monolog via the [monolog](https://www.drupal.org/project/monolog) module.
 - [Aimeos ecommerce framework](https://aimeos.org/) is usable with Monolog via the [ai-monolog](https://github.com/aimeos/ai-monolog) extension.
 - [Magento](https://magento.com/) comes out of the box with Monolog.