Add cloud providers examples

[fabioDMFerreira]

• [ ] AWS
• [ ] Azure
• [ ] Open Stack
• [ ] Vsphere
• [ ] Digital Ocean
• [ ] Upcloud
• [ ] Oci

[fabioDMFerreira]

https://github.com/hashicorp/terraform-provider-aws doesn't support importing raw image files from s3 as snapshots. This blocks the creation of a Nanos image using a terraform file.

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ami#image_location