Replace the `ahmetb/gen-crd-api-reference-docs` with `elastic/crd-ref-docs` in all MCM repos

[thiyyakat]

How to categorize this issue?

/area documentation
/kind enhancement
/priority 3

What would you like to be added:

Replace ahmetb/gen-crd-api-reference-docs with elastic/crd-ref-docs in all mcm repositories:

• machine-controller-manager
• machine-controller-manager-provider-aws
• machine-controller-manager-provider-azure
• machine-controller-manager-provider-gcp
• machine-controller-manager-provider-alicloud
• machine-controller-manager-provider-openstack (additionally, also check if dependency on g/g can be removed)

Why is this needed:

MCM uses ahmetb/gen-crd-api-reference-docs for generating API reference documentation, however this tool is no longer actively being maintained.