Add support for nested virtualization

[brilong]

AWS announced support for nested virtualization. The hashicorp/aws module v6.33.0 added support for the same.

Please add support for the nested virtualization CPU option.

[stuartp44]

Hey @brilong, thanks for the feedback. In terms of this open source project, if you feel it's useful, it's maybe worth contributing to the project. Adding features is typically reflective of what users would like to see in their own workflow/infra and, as a result, contributes to the project. This project is truly open source and needs people to contribute ideas like yours.

In terms of the work in progress, we will monitor this and once ready for review, we can get it reviewed and merged.