Update README to say project is no longer maintained

README.md

@@ -3,6 +3,8 @@
 [![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-v1.4%20adopted-ff69b4.svg)](CODE_OF_CONDUCT.md)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT) [![Join the chat at https://gitter.im/Kiln-security/community](https://badges.gitter.im/Kiln-security/community.svg)](https://gitter.im/Kiln-security/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
+:warning: Kiln is no longer maintained! 
+
 Kiln is an application security toolset that enables security teams to find vulnerabilities in their projects and derive insights from the data produced. Kiln makes it easy to run a range of open-source security tools on project repositories and automatically push notifications about issues to relevant teams through connectors such as Slack. The data that Kiln gathers from running open-source security tools on application repositories can be analyzed to gain useful insights into an organization's application security posture. This in turn enables the security team to make data-driven decisions about remediation and training. Kiln has been designed as a collection of dockerised application security tools, a validating HTTP proxy to forward the tool output to an Apache Kafka cluster and a collection of connectors to consume data from the Apache Kafka cluster.
 Some of the current use cases for Kiln are: