Add redis cluster docs.

Author: dereuromark

en/appendices/5-3-migration-guide.rst

@@ -64,6 +64,12 @@ Command
 - ``cake server`` now supports a ``--frankenphp`` option that will start the
   development server with `FrankenPHP <https://frankenphp.dev/>`__.
 
+Cache
+-----
+
+- Added Redis Cluster support to ``RedisEngine``. Configure the ``cluster`` option
+  with an array of server addresses to enable cluster mode.
+
 Console
 -------
 

en/core-libraries/caching.rst

@@ -173,10 +173,33 @@ RedisEngine uses the following engine specific options:
 * ``ssl_key`` The ssl private key used for TLS connections.
 * ``ssl_ca`` The ssl certificate authority file for TLS connections.
 * ``ssl_cert`` The ssl certificate used for TLS connections.
+* ``cluster`` Array of cluster server addresses for Redis Cluster support.
 
 .. versionadded:: 5.1.0
     TLS connections were added in 5.1
 
+.. versionadded:: 5.3.0
+    Redis Cluster support was added in 5.3
+
+Redis Cluster Configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To use Redis Cluster, configure the ``cluster`` option with an array of server addresses::
+
+    Cache::setConfig('redis_cluster', [
+        'className' => 'Redis',
+        'duration' => '+1 hours',
+        'prefix' => 'cake_redis_',
+        'cluster' => [
+            '127.0.0.1:7000',
+            '127.0.0.1:7001',
+            '127.0.0.1:7002',
+        ]
+    ]);
+
+When using Redis Cluster, the ``host`` and ``port`` options are ignored. The engine will
+automatically handle key distribution and failover across the cluster nodes.
+
 MemcacheEngine Options
 ----------------------