📖 Update docs to reference v1alpha3

[akutz]

What does this PR do, and why is it needed?

This patch updates the content under the docs directory to reference v1alpha3 for all examples.

Which issue(s) is/are addressed by this PR? (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):

Fixes NA

Are there any special notes for your reviewer:

Please add a release note if necessary:

Update ./docs content to reference v1alpha3.

---

📚 Documentation preview 📚: https://vm-operator--488.org.readthedocs.build/en/488/

[github-actions]

Package	Line Rate	Health
github.com/vmware-tanzu/vm-operator/api/v1alpha1	42%	❌
github.com/vmware-tanzu/vm-operator/api/v1alpha2	5%	❌
github.com/vmware-tanzu/vm-operator/controllers/contentlibrary/clustercontentlibraryitem	82%	✔
github.com/vmware-tanzu/vm-operator/controllers/contentlibrary/contentlibraryitem	86%	✔
github.com/vmware-tanzu/vm-operator/controllers/contentlibrary/utils	32%	❌
github.com/vmware-tanzu/vm-operator/controllers/infra/configmap	73%	➖
github.com/vmware-tanzu/vm-operator/controllers/infra/node	77%	➖
github.com/vmware-tanzu/vm-operator/controllers/infra/secret	77%	➖
github.com/vmware-tanzu/vm-operator/controllers/util/encoding	73%	➖
github.com/vmware-tanzu/vm-operator/controllers/virtualmachine	70%	➖
github.com/vmware-tanzu/vm-operator/controllers/virtualmachineclass	21%	❌
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinepublishrequest	81%	✔
github.com/vmware-tanzu/vm-operator/controllers/virtualmachineservice	83%	✔
github.com/vmware-tanzu/vm-operator/controllers/virtualmachineservice/providers	92%	✔
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinesetresourcepolicy	81%	✔
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinewebconsolerequest/v1alpha1	72%	➖
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinewebconsolerequest/v1alpha1/conditions	88%	✔
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinewebconsolerequest/v1alpha1/patch	78%	➖
github.com/vmware-tanzu/vm-operator/controllers/virtualmachinewebconsolerequest/v1alpha2	73%	➖
github.com/vmware-tanzu/vm-operator/controllers/volume	85%	✔
github.com/vmware-tanzu/vm-operator/pkg/conditions	88%	✔
github.com/vmware-tanzu/vm-operator/pkg/config	100%	✔
github.com/vmware-tanzu/vm-operator/pkg/config/env	100%	✔
github.com/vmware-tanzu/vm-operator/pkg/patch	16%	❌
github.com/vmware-tanzu/vm-operator/pkg/prober	54%	❌
github.com/vmware-tanzu/vm-operator/pkg/prober/probe	91%	✔
github.com/vmware-tanzu/vm-operator/pkg/prober/worker	77%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere	71%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/client	57%	❌
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/clustermodules	71%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/config	72%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/contentlibrary	72%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/credentials	100%	✔
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/network	80%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/placement	77%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/session	36%	❌
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/sysprep	100%	✔
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/vcenter	79%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/virtualmachine	77%	➖
github.com/vmware-tanzu/vm-operator/pkg/providers/vsphere/vmlifecycle	65%	➖
github.com/vmware-tanzu/vm-operator/pkg/record	78%	➖
github.com/vmware-tanzu/vm-operator/pkg/topology	55%	❌
github.com/vmware-tanzu/vm-operator/pkg/util	78%	➖
github.com/vmware-tanzu/vm-operator/pkg/util/cloudinit	89%	✔
github.com/vmware-tanzu/vm-operator/pkg/util/cloudinit/validate	91%	✔
github.com/vmware-tanzu/vm-operator/pkg/util/image	100%	✔
github.com/vmware-tanzu/vm-operator/pkg/util/kube	90%	✔
github.com/vmware-tanzu/vm-operator/pkg/util/vmopv1	89%	✔
github.com/vmware-tanzu/vm-operator/pkg/util/vsphere/client	68%	➖
github.com/vmware-tanzu/vm-operator/pkg/util/vsphere/vm	78%	➖
github.com/vmware-tanzu/vm-operator/pkg/webconsolevalidation	51%	❌
github.com/vmware-tanzu/vm-operator/webhooks/common	100%	✔
github.com/vmware-tanzu/vm-operator/webhooks/persistentvolumeclaim/validation	95%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachine/mutation	86%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachine/validation	95%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachineclass/mutation	62%	➖
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachineclass/validation	89%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachinepublishrequest/validation	92%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachineservice/mutation	67%	➖
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachineservice/validation	92%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachinesetresourcepolicy/validation	89%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachinewebconsolerequest/v1alpha1/validation	92%	✔
github.com/vmware-tanzu/vm-operator/webhooks/virtualmachinewebconsolerequest/v1alpha2/validation	92%	✔
Summary	56% (7922 / 14247)	❌