Update the comparison table with Kafka support (#461) (#462)

(cherry picked from commit 19291c3)

Co-authored-by: nima <[email protected]>

Author: mergify[bot]

docs/en/ingest-management/beats-agent-comparison.asciidoc

@@ -90,8 +90,8 @@ NOTE: {elastic-defend} and APM Server have a different output matrix.
 
 |Kafka
 |{y}
-|Under consideration
-|Under consideration
+|{y} (beta)
+|{y} (beta)
 
 |Redis
 |{y}