Add Managed Kafka page to latest docs (#6166)

* Add Page to Summary.md

* Create managed_kafka.md

* Edit docs filename

* Adjust deleted tab

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* Broken Links

* Remove links top of page

docs-gb/SUMMARY.md

@@ -16,6 +16,7 @@
       * [Strimzi SASL Example](getting-started/kubernetes-installation/security/strimzi-sasl.md)
       * [Reference](getting-started/kubernetes-installation/security/reference.md)
   * [Configuration](getting-started/configuration.md)
+      * [Managed Kafka](getting-started/managed-kafka.md)
   * [Seldon CLI](getting-started/cli.md)
 * [APIs](apis/README.md)
   * [Internal](apis/internal/README.md)