Add Maven Central badge

Author: acogoluegnes

README.adoc

@@ -1,5 +1,6 @@
 = RabbitMQ Stream Java Client
 
+image:https://maven-badges.herokuapp.com/maven-central/com.rabbitmq/stream-client/badge.svg["Maven Central", link="https://maven-badges.herokuapp.com/maven-central/com.rabbitmq/stream-client"]
 image:https://github.com/rabbitmq/rabbitmq-stream-java-client/workflows/Build%20(Linux)/badge.svg?branch=main["Build Status", link="https://github.com/rabbitmq/rabbitmq-stream-java-client/actions?query=workflow%3A%22Build+%28Linux%29%22+branch%3Amain"]
 image:https://codecov.io/gh/rabbitmq/rabbitmq-stream-java-client/branch/main/graph/badge.svg?token=CFZ6EHW47J["Code Coverage", link="https://codecov.io/gh/rabbitmq/rabbitmq-stream-java-client"]