Add dns page to explain how to use the flag inside site/ folder

site/content/en/docs/Reference/Networking/dns.md

@@ -0,0 +1,58 @@
+---
+title: "DNS Domain"
+linkTitle: "DNS Domain"
+weight: 6
+date: 2019-10-09
+description: >
+  Use configured DNS domain in bootstrapper kubeadm
+---
+
+minikube by default uses **cluster.local** if none is specified via the start flag --dns-domain. The configuration file used by kubeadm are found inside **/var/tmp/minikube/kubeadm.yaml** directory inside minikube.
+
+Default DNS configuration will look like below
+
+```
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: InitConfiguration
+localAPIEndpoint:
+......
+......
+---
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: ClusterConfiguration
+.....
+.....
+kubernetesVersion: v1.16.0
+networking:
+  dnsDomain: cluster.local
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+```
+
+To change the dns pass the value when starting minikube 
+
+```
+minikube start --dns-domain bla.blah.blah   
+```
+
+the dns now changed to bla.blah.blah
+
+```
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: InitConfiguration
+localAPIEndpoint:
+......
+......
+---
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: ClusterConfiguration
+.....
+.....
+kubernetesVersion: v1.16.0
+networking:
+  dnsDomain: bla.blah.blah
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+```