updating README.md: new note about updating credentials

Author: Julien Neuhart

README.md

@@ -155,6 +155,10 @@ Only the configuration files and the application source code are directly mounte
 The data of others services (like MySQL) are mounted using named volumes. You can locate these volumes
 on the host by utilizing the `docker inspect` command.
 
+**Note:** For now, the credentials will only be set the first time the Graylog, MySQL, RabbitMQ container are launched. 
+If you want to update them after, use the considered dashboard. You could also delete the named volumes, but proceed with 
+caution: it will also delete all your data.
+
 **Tip:** Your `app` folder should be a git submodule.
 
 ### Configuration files
@@ -367,10 +371,6 @@ You may access to the RabbitMQ dashboard (https://rabbitmq.my-awesome-project.lo
 | rabbitmq.user     | `kickoff.yml` | The RabbitMQ user of your PHP application.                  |
 | RABBITMQ_PASSWORD | `.env`        | The password of the user defined in the `kickoff.yml` file. |
 
-**Note:** The credentials will only be set the first time the RabbitMQ container is launched. If you want to update them 
-after, use the RabbitMQ dashboard. You could also delete the RabbitMQ named volume, but proceed with caution: it will also 
-delete all your queues, messages and so on.
-
 ## Contributing
 
 Please read our [contributing guidelines](.github/CONTRIBUTING.md) for instructions.