Add RabbitMQ as recommended system-requirement (#16885)

* Add RabbitMQ as recommended system-requirement

* Add a RabbitMQ configuration example

* Get back Doctrine-DSN and mention RabbitMQ only as a comment

* Correct wording

doc/01_Getting_Started/02_Advanced_Installation_Topics/01_Symfony_Messenger.md

@@ -13,10 +13,12 @@ framework:
 
             pimcore_core:
                 dsn: "doctrine://default?queue_name=pimcore_core"
+                # For RabbitMQ (recommended) use this as example:
+                # dsn: "amqp://rabbitmq:5672/%2f/pimcore_core"
                 failure_transport: pimcore_failed_jobs
 ```
 which can be re-processed later after fixing the underlying issue with command `bin/console messenger:consume pimcore_failed_jobs`.
 
 Please follow the [Symfony docs](https://symfony.com/doc/current/messenger.html#saving-retrying-failed-messages) for options on failed jobs processing.
 
-We recommend [RabbitMQ](https://www.rabbitmq.com/#getstarted) as a message queue. For a tutorial, check this [link](https://www.rabbitmq.com/tutorials/tutorial-one-php.html).
+We recommend [RabbitMQ](https://www.rabbitmq.com/#getstarted) as a message queue. For a tutorial, check this [link](https://www.rabbitmq.com/tutorials/tutorial-one-php.html). For an example configuration, refer to [this link](https://github.com/pimcore/skeleton/blob/11.x/.docker/messenger.yaml).

doc/23_Installation_and_Upgrade/01_System_Requirements.md

@@ -91,12 +91,16 @@ maxmemory-policy volatile-lru
 save ""
 ```
 
+### RabbitMQ (optional but recommended for messenger)
+Pimcore utilizes the Symfony Messenger for various background processes to ensure efficient handling of tasks. As the number of Pimcore elements grows, the need for a more robust and scalable queue system becomes evident. RabbitMQ is recommended in these scenarios for its exemplary performance and scalability. It excels in managing high volumes of messages and complex workflows, making it the preferred choice for systems that demand reliability and efficiency at scale.
+
+Please follow [Symfony Messenger](../01_Getting_Started/02_Advanced_Installation_Topics/01_Symfony_Messenger.md) for more information about pimcore messenger. For an example configuration, refer to [this link](https://github.com/pimcore/skeleton/blob/11.x/.docker/messenger.yaml).
+
 ### Operating System
 Please ensure you have installed all required packages to ensure proper locale support by PHP.
 On Debian based systems, you can use the following command to install all required packages: 
 `apt-get install locales-all` (on some systems there may be a reboot required).
 
-
 ### Additional Server Software 
 - FFMPEG (>= 3)
 - Ghostscript (>= 9.16)