Adds "helm repo add" to minikube.md TLDR
Adds "helm repo add" to minikube.md TLDR

Fix for issue #172

att-comdev/openstack-helm,att-comdev/openstack-helm,andrecolin/openstack-helm,andrecolin/openstack-helm,ss7pro/aic-helm,att-comdev/openstack-helm,ss7pro/aic-helm