Include cert manager as an installation requirement

README.md

@@ -9,8 +9,9 @@ Kubernetes operator to manage [RabbitMQ](https://www.rabbitmq.com/) messaging to
 Before deploying Messaging Topology Operator, you need to have:
 
 1. A Running k8s cluster
-2. RabbitMQ [Cluster Operator](https://github.com/rabbitmq/cluster-operator) installed in the k8s cluster
-3. A [RabbitMQ cluster](https://github.com/rabbitmq/cluster-operator/tree/main/docs/examples) deployed using the Cluster Operator
+2. [Cert Manager](https://cert-manager.io/docs/installation/kubernetes/) installed in the k8s cluster
+3. RabbitMQ [Cluster Operator](https://github.com/rabbitmq/cluster-operator) installed in the k8s cluster
+4. A [RabbitMQ cluster](https://github.com/rabbitmq/cluster-operator/tree/main/docs/examples) deployed using the Cluster Operator
 
 If you have `kubectl` configured to access your running k8s cluster, you can then run the following command to install the Messaging Topology Operator: