minor #14956 [Messenger] Document DSN format for Redis Cluster (nesk)

This PR was merged into the 5.3-dev branch.

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[Messenger] Document DSN format for Redis Cluster

Document Redis Cluster support for the Messenger component.

Related to symfony/symfony#40155

Commits
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243d84b [Messenger] Document DSN format for Redis Cluster

Author: xabbuh

messenger.rst

@@ -1329,6 +1329,8 @@ The Redis transport DSN may looks like this:
     MESSENGER_TRANSPORT_DSN=redis://localhost:6379/messages
     # Full DSN Example
     MESSENGER_TRANSPORT_DSN=redis://password@localhost:6379/messages/symfony/consumer?auto_setup=true&serializer=1&stream_max_entries=0&dbindex=0
+    # Redis Cluster Example
+    MESSENGER_TRANSPORT_DSN=redis://host-01:6379,redis://host-02:6379,redis://host-03:6379,redis://host-04:6379
     # Unix Socket Example
     MESSENGER_TRANSPORT_DSN=redis:///var/run/redis.sock