Replace kubepkg reference with krel templates

The `krel` templates are the ones we use right now, while kubepkg got
removed in kubernetes/release#3313.

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

content/en/docs/setup/production-environment/tools/kubeadm/install-kubeadm.md

@@ -371,10 +371,10 @@ cd $DOWNLOAD_DIR
 sudo curl -L --remote-name-all https://dl.k8s.io/release/${RELEASE}/bin/linux/${ARCH}/{kubeadm,kubelet}
 sudo chmod +x {kubeadm,kubelet}
 
-RELEASE_VERSION="v0.15.1"
-curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/kubepkg/templates/latest/deb/kubelet/lib/systemd/system/kubelet.service" | sed "s:/usr/bin:${DOWNLOAD_DIR}:g" | sudo tee /etc/systemd/system/kubelet.service
+RELEASE_VERSION="v0.16.2"
+curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubelet/kubelet.service" | sed "s:/usr/bin:${DOWNLOAD_DIR}:g" | sudo tee /etc/systemd/system/kubelet.service
 sudo mkdir -p /etc/systemd/system/kubelet.service.d
-curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/kubepkg/templates/latest/deb/kubeadm/10-kubeadm.conf" | sed "s:/usr/bin:${DOWNLOAD_DIR}:g" | sudo tee /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
+curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf" | sed "s:/usr/bin:${DOWNLOAD_DIR}:g" | sudo tee /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
 ```
 
 Install `kubectl` by following the instructions on [Install Tools page](/docs/tasks/tools/#kubectl).

content/en/docs/setup/production-environment/tools/kubeadm/kubelet-integration.md

@@ -162,12 +162,10 @@ Kubeadm deletes the `/etc/kubernetes/bootstrap-kubelet.conf` file after completi
 Note that the kubeadm CLI command never touches this drop-in file.
 
 This configuration file installed by the `kubeadm`
-[DEB](https://github.com/kubernetes/release/blob/master/cmd/kubepkg/templates/latest/deb/kubeadm/10-kubeadm.conf) or
-[RPM package](https://github.com/kubernetes/release/blob/master/cmd/kubepkg/templates/latest/rpm/kubeadm/10-kubeadm.conf) is written to
+[package](https://github.com/kubernetes/release/blob/cd53840/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf) is written to
 `/etc/systemd/system/kubelet.service.d/10-kubeadm.conf` and is used by systemd.
 It augments the basic
-[`kubelet.service` for RPM](https://github.com/kubernetes/release/blob/master/cmd/kubepkg/templates/latest/rpm/kubelet/kubelet.service) or
-[`kubelet.service` for DEB](https://github.com/kubernetes/release/blob/master/cmd/kubepkg/templates/latest/deb/kubelet/lib/systemd/system/kubelet.service):
+[`kubelet.service`](https://github.com/kubernetes/release/blob/cd53840/cmd/krel/templates/latest/kubelet/kubelet.service):
 
 {{< note >}}
 The contents below are just an example. If you don't want to use a package manager