update doc for Cluster

Signed-off-by: sivchari <shibuuuu5@gmail.com>

Author: sivchari

docs/book/src/developer/providers/getting-started/building-running-and-testing.md

@@ -140,7 +140,7 @@ You best watch the Kubernetes pods with something like `k9s -A` or `watch kubect
 Let's try our cluster out. We'll make some simple YAML:
 
 ```yaml
-apiVersion: cluster.x-k8s.io/v1beta1
+apiVersion: cluster.x-k8s.io/v1beta2
 kind: Cluster
 metadata:
   name: hello-mailgun
@@ -149,7 +149,7 @@ spec:
     pods:
       cidrBlocks: ["192.168.0.0/16"]
   infrastructureRef:
-    apiVersion: infrastructure.cluster.x-k8s.io/v1alpha1
+    apiGroup: infrastructure.cluster.x-k8s.io
     kind: MailgunCluster
     name: hello-mailgun
 ---

docs/book/src/tasks/bootstrap/kubeadm-bootstrap/index.md

@@ -17,18 +17,18 @@ infrastructure object.
 
 ```yaml
 kind: DockerCluster
-apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+apiVersion: infrastructure.cluster.x-k8s.io/v1beta2
 metadata:
   name: my-cluster-docker
 ---
 kind: Cluster
-apiVersion: cluster.x-k8s.io/v1beta1
+apiVersion: cluster.x-k8s.io/v1beta2
 metadata:
   name: my-cluster
 spec:
   infrastructureRef:
     kind: DockerCluster
-    apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+    apiGroup: infrastructure.cluster.x-k8s.io
     name: my-cluster-docker
 ```
 

docs/book/src/tasks/bootstrap/microk8s-bootstrap.md

@@ -13,11 +13,11 @@ Cluster API bootstrap provider MicroK8s (CABPM) is a component responsible for g
 MicroK8s defines a `MicroK8sControlPlane` definition as well as the `MachineDeployment` to configure the control plane and worker nodes respectively. The `MicroK8sControlPlane` is linked in the cluster definition as shown in the following example:
 
 ```yaml
-apiVersion: cluster.x-k8s.io/v1beta1
+apiVersion: cluster.x-k8s.io/v1beta2
 kind: Cluster
 spec:
   controlPlaneRef:
-    apiVersion: controlplane.cluster.x-k8s.io/v1beta1
+    apiGroup: controlplane.cluster.x-k8s.io
     kind: MicroK8sControlPlane
     name: capi-aws-control-plane
 ```

docs/book/src/tasks/workload-bootstrap-gitops.md

@@ -14,7 +14,7 @@ Follow the quickstart setup guide for your provider but ensure that CAAPH is ins
 Add the labels `argoCDChart: enabled` and `guestbook: enabled` to your desired workload cluster yaml file in the `Cluster` metadata section, for example:
 
 ```yaml
-apiVersion: cluster.x-k8s.io/v1beta1
+apiVersion: cluster.x-k8s.io/v1beta2
 kind: Cluster
 metadata:
   name: my-cluster