Refine Notifier component configuration guidance

Added detailed instructions to configure the Symfony Notifier component correctly, emphasizing proper setup for SMS providers like OVHcloud. Clarified removal of legacy configurations and included examples for both utilizing and replacing the added configuration.

.changes/v3.7.0.md

@@ -1,5 +1,62 @@
 ## v3.7.0 - 2025-01-21
 ### Feature
-* Use the Notifier component from Symfony to sens short messages (SMS). This allow to use more provider.    
+* Use the Notifier component from Symfony to sens short messages (SMS). This allow to use more provider.
 ### Fixed
-* ([#348](https://gitlab.com/Chill-Projet/chill-bundles/-/issues/348)) [export] Fix aggregation of referrer's scope and job: fix the date range comparison   
+* ([#348](https://gitlab.com/Chill-Projet/chill-bundles/-/issues/348)) [export] Fix aggregation of referrer's scope and job: fix the date range comparison
+
+### Warning on configuration of Notifier component
+
+If installed in an symfony app where the recipes are activated, this configuration should be added automatically:
+
+```yaml
+framework:
+    notifier:
+        chatter_transports:
+        texter_transports:
+            ovhcloud: '%env(OVHCLOUD_DSN)%'
+        channel_policy:
+            # use chat/slack, chat/telegram, sms/twilio or sms/nexmo
+            urgent: ['email']
+            high: ['email']
+            medium: ['email']
+            low: ['email']
+        admin_recipients:
+            - { email: admin@example.com }
+```
+
+Actually, you should either:
+
+- remove the configuration of ovhcloud added by the recipe
+- or remove the previous configuration of chill, to avoid keeping legacy configuration
+
+#### Remove the added configuration and keep the legacy configuration
+
+To remove the configuration:
+
+```diff
+framework:
+    notifier:
+        chatter_transports:
+        texter_transports:
+-            ovhcloud: '%env(OVHCLOUD_DSN)%'
+```
+
+In that case, the previous configuration, which was stored under the `chill_main.short_messages.dsn` will be reconfigured into the Notifier component's configuration.
+
+#### Properly configure SMS
+
+You can also properly configure it, as [described in the OVH cloud provider repository](https://github.com/symfony/ovh-cloud-notifier/tree/5.4?tab=readme-ov-file#dsn-example) (where the scheme is `ovhcloud`):
+
+**NOTE**: You have access to all notifier available with the [Notifier component](https://symfony.com/doc/current/notifier.html#notifier-sms-channel). You are not restricted to use OVH as a provider.
+
+```diff
+framework:
+    notifier:
+        chatter_transports:
+        texter_transports:
++            ovhcloud: '%env(OVHCLOUD_DSN)%' # this value should be located in a variable, and have `ovhcloud://` as a scheme
+
+chill_main:
+-    short_messages:
+-        dsn: '%env(string:SHORT_MESSAGE_DSN)%'
+```