AKS Intro Hack: Kubernetes Dashboard is deprecated and should be removed

[larryclaman]

Challenge 3 https://github.com/microsoft/WhatTheHack/blob/master/001-IntroToKubernetes/Student/03-k8sintro.md in the Intro to Kubernetes hack suggests that students check out the Kubernetes Dashboard.
I suggest that we remove/refactor this part, as the Kubernetes Dashboard has been deprecated in AKS: https://docs.microsoft.com/en-us/azure/aks/kubernetes-dashboard

[larryclaman]

closing this issue as I rolled it into my PR #207