Fix typo in reference documentation.

Closes #3018

Author: Seungpang

src/main/antora/modules/ROOT/pages/redis/cluster.adoc

@@ -44,7 +44,7 @@ b8b5ee... 127.0.0.1:7382 slave 6b38bb... 0 1449730618304 25 connected          <
 
 [source,java]
 ----
-RedisClusterConnection connection = connectionFactory.getClusterConnnection();
+RedisClusterConnection connection = connectionFactory.getClusterConnection();
 
 connection.set("thing1", value);                                               <5>
 connection.set("thing2", value);                                               <6>
@@ -88,7 +88,7 @@ [email protected]:7379 > cluster nodes
 
 [source,java]
 ----
-RedisClusterConnection connection = connectionFactory.getClusterConnnection();
+RedisClusterConnection connection = connectionFactory.getClusterConnection();
 
 connection.set("thing1", value);           // slot: 12182
 connection.set("{thing1}.thing2", value);  // slot: 12182
@@ -133,3 +133,6 @@ clusterOps.shutdown(NODE_7379);                                              <1>
 
 <1> Shut down node at 7379 and cross fingers there is a replica in place that can take over.
 ====
+
+NOTE: Redis Cluster pipelining is currently only supported through the Lettuce driver except for the following commands when using cross-slot keys: `rename`, `renameNX`, `sort`, `bLPop`, `bRPop`, `rPopLPush`, `bRPopLPush`, `info`, `sMove`, `sInter`, `sInterStore`, `sUnion`, `sUnionStore`, `sDiff`, `sDiffStore`.
+Same-slot keys are fully supported.

src/main/antora/modules/ROOT/pages/redis/redis-cache.adoc

@@ -47,7 +47,7 @@ It is possible to opt in to the locking behavior as follows:
 
 [source,java]
 ----
-RedisCacheManager cacheMangager = RedisCacheManager
+RedisCacheManager cacheManager = RedisCacheManager
     .build(RedisCacheWriter.lockingRedisCacheWriter(connectionFactory))
     .cacheDefaults(RedisCacheConfiguration.defaultCacheConfig())
     ...