Add example for the IngressClass usage

docs/content/providers/kubernetes-ingress.md

@@ -264,7 +264,33 @@ Otherwise, Ingresses missing the annotation, having an empty value, or with the
     the new `IngressClass` resource can be leveraged to identify Ingress objects that should be processed.
     In that case, Traefik will look for an `IngressClass` in the cluster with the controller value equal to *traefik.io/ingress-controller*. 
     
-    Please see [this article](https://kubernetes.io/blog/2020/04/02/improvements-to-the-ingress-api-in-kubernetes-1.18/) for more information.
+    Please see [this article](https://kubernetes.io/blog/2020/04/02/improvements-to-the-ingress-api-in-kubernetes-1.18/) for more information or the example below.
+
+    ```yaml tab="IngressClass"
+    apiVersion: networking.k8s.io/v1beta1
+    kind: IngressClass
+    metadata: 
+      name: traefik-lb
+    spec: 
+      controller: traefik.io/ingress-controller
+    ```
+  
+    ```yaml tab="Ingress"
+    apiVersion: "networking.k8s.io/v1beta1"
+    kind: "Ingress"
+    metadata:
+      name: "example-ingress"
+    spec:
+      ingressClassName: "traefik-lb"
+      rules:
+      - host: "*.example.com"
+        http:
+          paths:
+          - path: "/example"
+            backend:
+              serviceName: "example-service"
+              servicePort: 80
+    ```
 
 ### `ingressEndpoint`