add `make describe`

[smarunich]

Port it from tse sandbox

❯ make describe
Welcome to Tetrate Service Express Demo Environment on AWS Elastic Kubernetes Service using Terraform
- Tetrate Service Express Management Plane is reachable at https://k8s-tse-envoy-5294de6f93-7793a5233d6b895c.elb.us-west-1.amazonaws.com with username username: tse and password: tse
- Please consult KB for tctl access: https://docs-preview.tetrate.io/service-express/Tech-Preview/installation/management-plane#access-the-management-plane-using-a-web-browser
- tctl access is also provided using jumpboxes, please consult for outputs folder - ssh-to-aws scripts to reach any of the deployed jumpboxes
- for kubernetes cluster access, please consult for outputs folder for generate-*-kubeconfig scripts to generate and consume kubeconfig files
- List of provisioned Kubernetes clusters:
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        ID      |       CLUSTER_NAME                    |       REGION          |       K8S_VERSION
--------------------------------------------------------------------------------------------------------------------
        0       |       170p4demo3-0-us-west-1          |       us-west-1       |       1.26
        1       |       170p4demo3-1-us-east-1          |       us-east-1       |       1.26
--------------------------------------------------------------------------------------------------------------------