Add a Gitter chat badge to README.md (#30)

* Add Gitter badge

* Update README.md

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

Author: gitter-badger

Diff for: README.md

@@ -3,13 +3,13 @@
 [![Supported librdkafka versions: >= 1.4.0](https://img.shields.io/badge/librdkafka-%3E%3D%201.4.0-blue.svg)](https://github.com/edenhill/librdkafka/releases) 
 [![Supported Kafka versions: >= 0.9](https://img.shields.io/badge/kafka-%3E%3D%200.9-blue.svg)](https://github.com/edenhill/librdkafka/blob/master/INTRODUCTION.md#broker-version-compatibility) 
 ![Supported PHP versions: 7.x .. 8.x](https://img.shields.io/badge/php-7.x%20..%208.x-blue.svg)
-[![License: BSD-3](https://img.shields.io/badge/License-BSD--3-green.svg)](https://github.com/php-kafka/php-kafka/blob/main/LICENSE)
+[![License: BSD-3](https://img.shields.io/badge/License-BSD--3-green.svg)](https://github.com/php-kafka/php-kafka/blob/main/LICENSE) [![Join the chat at https://gitter.im/php-kafka/php-simple-kafka-client](https://badges.gitter.im/php-kafka/php-simple-kafka-client.svg)](https://gitter.im/php-kafka/php-simple-kafka-client?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 ## Documentation
 Please read the documentation [here](https://php-kafka.github.io/php-simple-kafka-client.github.io/about/)
 
 ## Support
-Join the [Slack Workspace](https://join.slack.com/t/php-kafka/shared_invite/zt-a73huj9v-Nl3n9RjGgjrE8OI4bfsH6Q) or [Gitter](https://gitter.im/php-kafka/php-kafka)
+Join the [Slack Workspace](https://join.slack.com/t/php-kafka/shared_invite/zt-a73huj9v-Nl3n9RjGgjrE8OI4bfsH6Q) or [Gitter](https://gitter.im/php-kafka/php-simple-kafka-client)
 
 ## Credits
 This extension relies on [librdkafka](https://github.com/edenhill/librdkafka)