Update Local setup with Vagrant documentation

Description

Update the Local Setup with Vagrant setup guide to work with the current version of Sandbox.

Why is this needed

Fixes: The guide as written doesn't work due to many changed directory paths, conflicting MAC addresses in the guide already existing in the repo, the docker registry requiring SSL now by default, and more. This is just a quick cleanup to make it at least function as written.

How Has This Been Tested?

Ran through the setup and validated the examples worked and provided the stated output.

Linux Ubuntu 20.04 with libvirt.

It doesn't touch any code, just this one documentation file.

How are existing users impacted? What migration steps/scripts do we need?

Documentation will actually work for the vagrant setup workflow.

Checklist:

I have:

[X] updated the documentation and/or roadmap (if required)
[O] added unit or e2e tests
[O] provided instructions on how to upgrade

tinkerbell / tinkerbell-docs