feat(kubeadm): add auto-completion plugin

plugins/kubeadm/README.md

@@ -0,0 +1,10 @@
+# kubeadm plugin
+
+This plugin adds completion for the [kubernetes cluster creator](https://kubernetes.io/docs/reference/setup-tools/kubeadm/).
+Kubeadm is a tool built to provide kubeadm init and kubeadm join as best-practice "fast paths" for creating Kubernetes clusters.
+
+To use it, add `kubeadm` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... kubeadm)
+```