GH-9862: Document caching for SMB sessions

Fixes: https://github.com/spring-projects/spring-integration/issues/9862

* Fix typo in the `message.adoc`

src/reference/antora/modules/ROOT/pages/message.adoc

@@ -433,4 +433,4 @@ class PiiMessage<P> extends GenericMessage<P> {
 }
 ----
 
-The this `PiiMessageBuilderFactory` could be registered as a bean, and whenever the framework logs the message (e.g. in case of `errorChannel`), the `password` header will be masked.
+Then this `PiiMessageBuilderFactory` could be registered as a bean, and whenever the framework logs the message (e.g. in case of `errorChannel`), the `password` header will be masked.

src/reference/antora/modules/ROOT/pages/smb.adoc

@@ -95,6 +95,23 @@ public SmbSessionFactory smbSessionFactory() {
 }
 ----
 
+[[smb-session-caching]]
+== SMB Session Caching
+
+The `SmbSessionFactory` initiates a new connection every time when a `Session` is requested.
+In most cases that is not necessary and `Session` could be cached.
+For that purpose, the `SmbSessionFactory` as mentioned earlier should be wrapped into an instance of `CachingSessionFactory`:
+[source,java]
+----
+@Bean
+public CachingSessionFactory cachingSessionFactory(SmbSessionFactory smbSessionFactory) {
+    cachingSessionFactory cachingSessionFactory = new CachingSessionFactory(smbSessionFactory, 10);
+    cachingSessionFactory.setSessionWaitTimeout(1000);
+    return cachingSessionFactory;
+}
+----
+And then its bean can be injected into channel adapters described below.
+
 [[smb-inbound]]
 == SMB Inbound Channel Adapter