Add some further Kubernetes to curriculum

[sre-is-laura]

there's one small thing with hpa on minikube; more kube would be helpful.
perhaps including writing a controller - modifying an existing controller could cover the 'more modification of existing code' goal also

[sre-is-laura]

Ideas from discussion with Daniel:

• introduce running the multiple-servers project on minikube
• then when we get to the kafka project, add another step onto that which is basically 'so now you have this running on docker-compose, move it onto minikube'

[sre-is-laura]

I plan to work on this in early April.