Add configmap on deployment instructions

examples/deployment/haproxy/README.md

@@ -55,6 +55,21 @@ NAME                                       READY     STATUS    RESTARTS   AGE
 ingress-default-backend-1110790216-gqr61   1/1       Running   0          10s
 ```
 
+## Configmap
+
+Create a configmap named `haproxy-ingress`:
+
+```console
+$ kubectl create configmap haproxy-ingress
+configmap "haproxy-ingress" created
+```
+
+A configmap is used to provide global or default configuration like
+timeouts, SSL/TLS settings, a syslog service endpoint and so on. The
+configmap can be edited or replaced later in order to apply new
+configuration on a running ingress controller. All supported options
+are [here](https://github.com/jcmoraisjr/haproxy-ingress#configmap).
+
 ## Controller
 
 Deploy HAProxy Ingress:

examples/deployment/haproxy/haproxy-ingress.yaml

@@ -20,6 +20,7 @@ spec:
         args:
         - --default-backend-service=default/ingress-default-backend
         - --default-ssl-certificate=default/tls-secret
+        - --configmap=default/haproxy-ingress
         ports:
         - name: http
           containerPort: 80