Support K3s config yaml (#252)

* Support K3s config yaml

Signed-off-by: Derek Nola <derek.nola@suse.com>

Vagrantfile

@@ -32,8 +32,11 @@ def provision(vm, role, node_num)
       # Required to use the private network configured above
       extra_server_args: "--node-external-ip #{node_ip} --flannel-iface eth1", 
       extra_agent_args: "--node-external-ip #{node_ip} --flannel-iface eth1",
-      # Not needed, left as reference for ruby-ansible list syntax
+      # Optional, left as reference for ruby-ansible syntax
       # extra_service_envs: [ "NO_PROXY='localhost'" ],
+      # config_yaml: <<~YAML
+      #   write-kubeconfig-mode: 644
+      # YAML
     }
   end
 end