[Doc][Improve] Add Support Kerberos Auth For Kafka Connector #6653 (#6660)

---------

Co-authored-by: tianxy105 <lucas123.COM>

Author: gitfortian

Diff for: docs/en/connector-v2/sink/Kafka.md

@@ -191,3 +191,25 @@ sink {
 }
 ```
 
+### Kerberos Authentication Example
+
+Sink Config
+
+```
+sink {
+    Kafka {
+        topic = "seatunnel"
+        bootstrap.servers = "127.0.0.1:9092"
+        format = json
+        semantics = EXACTLY_ONCE
+        kafka.config = {
+            security.protocol=SASL_PLAINTEXT
+            sasl.kerberos.service.name=kafka
+            sasl.mechanism=GSSAPI
+            java.security.krb5.conf="/etc/krb5.conf"
+            sasl.jaas.config="com.sun.security.auth.module.Krb5LoginModule required \n        useKeyTab=true \n        storeKey=true  \n        keyTab=\"/path/to/xxx.keytab\" \n        principal=\"[email protected]\";"
+        }
+    }
+}
+```
+

Diff for: docs/en/connector-v2/source/kafka.md

@@ -159,3 +159,24 @@ source {
 }
 ```
 
+### Kerberos Authentication Example
+
+Source Config
+
+```
+source {
+    Kafka {
+        topic = "seatunnel"
+        bootstrap.servers = "127.0.0.1:9092"
+        consumer.group = "seatunnel_group"
+        kafka.config = {
+            security.protocol=SASL_PLAINTEXT
+            sasl.kerberos.service.name=kafka
+            sasl.mechanism=GSSAPI
+            java.security.krb5.conf="/etc/krb5.conf"
+            sasl.jaas.config="com.sun.security.auth.module.Krb5LoginModule required \n        useKeyTab=true \n        storeKey=true  \n        keyTab=\"/path/to/xxx.keytab\" \n        principal=\"[email protected]\";"
+        }
+    }
+}
+```
+