Implement shared folders

[c4milo]

A shared folder resource does not exists outside of a virtual machine in VMware workstation. So, it is not possible to model it as a normal resource in Terraform. That's why we have to embed it inside the vix_vm resource.

This is how a block would look like for shared folders:

shared_folder {
        enable = false
        name = "Dev1"
        guest_path = "/home/camilo/dev"
        host_path = "/Users/camilo/Development"
        readonly = false
}