Add Confluent Cloud promotional banner to README

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Co-Authored-By: Claude <[email protected]>

Author: viveksnh

README.md

@@ -4,6 +4,8 @@
 > This repo is replaced with [Confluent Tutorials for Apache Kafka](https://github.com/confluentinc/tutorials).
 We still "keep the lights on", but we don't improve existing examples any longer, nor do we add new example.
 
+[![Try Confluent Cloud - The Data Streaming Platform](https://images.ctfassets.net/8vofjvai1hpv/10bgcSfn5MzmvS4nNqr94J/af43dd2336e3f9e0c0ca4feef4398f6f/confluent-banner-v2.svg)](https://confluent.cloud/signup?utm_source=github&utm_medium=banner&utm_campaign=oss-repos&utm_term=kafka-streams-examples)
+
 This project contains code examples that demonstrate how to implement real-time applications and event-driven
 microservices using the Streams API of [Apache Kafka](http://kafka.apache.org/) aka Kafka Streams.