Documentation: Instructions to update vSphere thumbprint

**What would you like to be added**:

When vSphere certificate is updated and Thumbprint has changed, we need instructions on how to reflect new thumbprint in EKSA Cluster to update new nodes if any existing nodes are deleted.

**Why is this needed**:
When thumbprint is changed for vCenter, new nodes cannot be added for existing EKS A Clusters.

- kubectl get [validatingwebhookconfigurations.admissionregistration.k8s.io]
(http://validatingwebhookconfigurations.admissionregistration.k8s.io/) capv-validating-webhook-configuration -o yaml > backup-capv-webhook.yaml

- kubectl get [validatingwebhookconfigurations.admissionregistration.k8s.io](http://validatingwebhookconfigurations.admissionregistration.k8s.io/) eksa-validating-webhook-configuration -o yaml > backup-eksa-webhook.yaml

- kubectl delete [validatingwebhookconfigurations.admissionregistration.k8s.io](http://validatingwebhookconfigurations.admissionregistration.k8s.io/) eksa-validating-webhook-configuration

- kubectl delete [validatingwebhookconfigurations.admissionregistration.k8s.io](http://validatingwebhookconfigurations.admissionregistration.k8s.io/) capv-validating-webhook-configuration

- kubectl edit [vspheredatacenterconfigs.anywhere.eks.amazonaws.com](http://vspheredatacenterconfigs.anywhere.eks.amazonaws.com/)

- Modify the spec.thumbprint to have the new values. Repeat for all the vspheredatacenterconfigs.

- kubectl edit [vspheremachinetemplates.infrastructure.cluster.x-k8s.io](http://vspheremachinetemplates.infrastructure.cluster.x-k8s.io/) -n eksa-system

- Modify the spec.template.spec.thumbprint to have the new value.

- kubectl edit configmaps -n kube-system vsphere-cloud-config

- Modify all entries of thumbprint in the configmap.

- This should resolve the issues with connecting to vsphere and bring the cluster back to a happy state. After which we can upgrade the cluster.

Start by locating the vSphere certificate or thumbprint documentation and compare it with the listed kubectl commands for validating webhook configurations, VSphereDataCenterConfigs, VSphereMachineTemplates, and the kube-system vsphere-cloud-config ConfigMap. Document the recovery procedure and verify that it explains updating every relevant thumbprint and restoring the cluster before an upgrade.

Written by the indexing model from the issue text.