One of the `sed` commands for updating the kubeadm systemd
file (`/etc/systemd/system/kubelet.service.d/10-kubeadm.conf`)
was missing a `-i` reference to the file itself, causing it
to hang indefinitely if ran as declared.
I also wrapped this second `sed` in an `if grep ...` check,
in order to make the operation idempotent.
* Documentation: Added kubeadm documentation #618
This getting started guide covers a simple deployment of kube-prometheus
and assumes you have deployed using kubeadm.
Hopefully this helps clears up #618
* Moved documentation to appropriate folder, updated links.
* Minor documentation editing
Fixed referneces to Alertmanager.
Slightly stronger wording on changing grafana user/pass
