Add support of MetalLB

Change-Id: I0ffdd78cd10642fc38cfab146127eae7359b5649
diff --git a/README.rst b/README.rst
index da82ccb..c9dc10a 100644
--- a/README.rst
+++ b/README.rst
@@ -476,6 +476,22 @@
         apiserver:
           secure_port: 8081
 
+Kubernetes with MetalLB
+-----------------------
+
+On Master:
+
+.. code-block:: yaml
+
+    kubernetes:
+      common:
+        addons:
+          metallb:
+            enabled: true
+            addresses:
+            - 172.16.10.150-172.16.10.180
+            - 172.16.10.192/26
+
 Kubernetes with Flannel
 -----------------------