Explicitly set namespace in all multi-node example resources

When deploying this I was mistakenly in another namespace and the
cluster install failed because the MachineDeployment and
OpenshiftAssistedConfigTemplate were in the wrong namespace.

Author: carbonin

examples/multi-node-example.yaml

@@ -131,6 +131,7 @@ apiVersion: cluster.x-k8s.io/v1beta1
 kind: MachineDeployment
 metadata:
   name: test-multinode-worker
+  namespace: test-capi
   labels:
     cluster.x-k8s.io/cluster-name: test-multinode
 spec:
@@ -159,6 +160,7 @@ apiVersion: bootstrap.cluster.x-k8s.io/v1alpha1
 kind: OpenshiftAssistedConfigTemplate
 metadata:
   name: test-multinode-worker
+  namespace: test-capi
   labels:
     cluster.x-k8s.io/cluster-name: test-multinode
 spec:
@@ -170,4 +172,4 @@ spec:
           - 'metal3.io/uuid="${METADATA_UUID}"'
       pullSecretRef:
         name: "pull-secret"
-      sshAuthorizedKey: <SSH_AUTHORIZED_KEY>
+      sshAuthorizedKey: <SSH_AUTHORIZED_KEY>