Docs - We are missing resources in the docs

[DavidGOrtega]

We do no have docs about machine and runner resources in https://registry.terraform.io/providers/iterative/iterative/latest/docs/resources/

[0x2b3bfa0]

🤔 Should we?

[casperdcl]

I think we should put docs about them in https://github.com/iterative/terraform-provider-iterative/wiki at least for now

[0x2b3bfa0]

After #461 this looks like won't fix or, at least, in dire need of reformulation