Kiam to be Maintenance only going forward (#509)

* explain that project is maintenance only in readme

Author: Joseph-Irving

README.md

@@ -2,6 +2,14 @@
 
 [![Docker Repository on Quay](https://quay.io/repository/uswitch/kiam/status "Docker Repository on Quay")](https://quay.io/repository/uswitch/kiam)
 
+## 🚨 ⚠️THIS PROJECT IS IN MAINTENANCE MODE ⚠️ 🚨
+
+We developed Kiam years ago as it solved a very specific problem for us as we tried to run applications in AWS on Kubernetes. Since then there have been a lot of advances in this space, the most significant being AWS' official solution: [IAM roles for Service Accounts](https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts.html). We believe this solution is significantly superior to Kiam and we have been internally moving away from Kiam for some time. We would encourage others to do the same.
+We are only a small team and we don't have the capacity to maintain a tool we don't use, so from now on we will only be accepting patches/bug fixes.
+Thank you to all the external contributors who have helped Kiam grow over the years.
+
+## About
+
 kiam runs as an agent on each node in your Kubernetes cluster and allows cluster users to associate IAM roles to Pods.
 
 Docker images are available at [https://quay.io/repository/uswitch/kiam](https://quay.io/repository/uswitch/kiam).