Add option to disable kube-vip (#385)

.config.sample.env

@@ -36,6 +36,11 @@ export BOOTSTRAP_METALLB_TRAEFIK_ADDR=""
 # e.g. age15uzrw396e67z9wdzsxzdk7ka0g2gr3l460e0slaea563zll3hdfqwqxdta
 export BOOTSTRAP_AGE_PUBLIC_KEY=""
 
+
+# Enable / Disable kube-vip
+# If this is set to false (e.g. on a cluster with a single-node control plane), do not install kube-vip.
+# BOOTSTRAP_KUBE_VIP_ADDR needs to be set to the IP the API Server is reachable under
+export BOOTSTRAP_KUBE_VIP_ENABLED="true"
 # The IP Address to use with KubeVIP
 # Pick a unused IP that is on the same network as your nodes
 # and outside the ${BOOTSTRAP_METALLB_LB_RANGE} range