feat: add vultr container registry resource

[im6h]

Description

• Based on Vultr API, add resource container registry and data container registry
• Add docs and examples to use the new resource

  Checklist:

• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• [x] Have you linted your code locally prior to submission?
• [x] Have you successfully ran tests with your changes locally?

[im6h]

I fixed golint and added resources to terrafrom code @optik-aper Would you like to check it again? Thanks

[Stealthmate]

I'd really like to see this merged! I'm in the process of writing TF manifests for all my stuff on Vultr, and container registry is one of the first things I need to have in order to bootstrap everything else.

I'm no Go expert, but I can hack on this and try to resolve the conflicts if needed.

[optik-aper]

Sorry for the delay! I'll test this out and merge it this afternoon.

[im6h]

I'd really like to see this merged! I'm in the process of writing TF manifests for all my stuff on Vultr, and container registry is one of the first things I need to have in order to bootstrap everything else.

I'm no Go expert, but I can hack on this and try to resolve the conflicts if needed.

Sure. I think we can make PR better before merging into the main

[F21]

Is there anything I can do to help with this one? Pretty keen to see this merged.

[optik-aper]

Is there anything I can do to help with this one? Pretty keen to see this merged.

I just tested things out and it's working. There are a few things I'd like to see cleaned up, and the name validation currently won't account for names with non-alphanumeric characters, but I will address that in a separate PR. I'll get a new release out today or tomorrow.