*: add complete CNI support

This commit enables Kilo to work as an independent networking provider.
This is done by leveraging CNI. Kilo brings the necessary CNI plugins to
operate and takes care of all networking.

Add-on compatibility for Calico, Flannel, etc, will be re-introduced
shortly.

docs/vpn.md

@@ -59,3 +59,10 @@ for ip in $(kgctl showconf peer $PEER | grep AllowedIPs | cut -f 3- -d ' ' | tr
 	sudo ip route add $ip dev $IFACE
 done
 ```
+
+Once the routes are in place, the connection to the cluster can be tested.
+For example, try connecting to the API server:
+
+```shell
+curl -k https://10.0.27.179:6443
+```