Apply Equinix TF Modules examples/ conventions (using existing samples)

[displague]

Apply Equinix TF Modules examples/ conventions (using existing samples).

For more on the conventions, see https://github.com/equinix-labs/equinix-labs/blob/main/terraform-modules.md; not all applied in this PR. More could be pulled in through adopting some of the CI and practices from https://github.com/equinix-labs/terraform-equinix-template/.

Removes managed storage options.

Continues #63

Fixes https://github.com/equinix/terraform-metal-openstack/issues/60

Blocked by:

• [ ] #67
• [ ] #68
• [ ] #69
• [ ] #70

[displague]

If not in this PR, than in a successor, the provider definition should move into the examples/ and the README.md should give instruction to run the project from the examples.