DOC-1154 update supported features in Serverless (#244)

* DOC-1154 update supported features in Serverless

* minor edit

Author: micheleRP

modules/get-started/pages/cluster-types/serverless.adoc

@@ -87,10 +87,14 @@ NOTE: Redpanda Serverless is opinionated about Kafka configurations. For example
 
 === Unsupported features
 
-* Data transforms
-* Redpanda Admin API 
+Not all features included in BYOC clusters are available in Serverless. For example, the following features are not supported:
+
 * HTTP Proxy API
-* Kafka Connect
+* Schema Registry UI (API is supported)
+* Metrics endpoints
+* Kafka Connect 
+* Private networking and multiple availability zones (AZs)
+* RBAC in the data plane and mTLS authentication for Kafka API clients
 
 == Next steps