Suggestion to add commands to the dashboard tutorial for clarity

[pauldipietro]

When following the guide to create a dashboard, a user will run into an error at step 3 if the kube-prometheus-stack repo isn't added. While it's mentioned on the repo which is linked on the tutorial page, I might suggest adding it directly to the tutorial for additional clarity, e.g.:

#Ensure helm repo for kube-prometheus-stack is added
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update

helm install -f values.yaml monitoring prometheus-community/kube-prometheus-stack