Start Terraform Migration

[nyarly]

Starting proper Terraform config

terraform-incubator/ holds working Terraform configuration
for the dev environment for People Depot.
Most of the configuration stitches together configuration from
existing terraform-modules work.

Separate shared_resources and people-depot

Allows the shared_resources to be reused across other projects.
The shared_resources/all module re-exports values using
a Terraform remote-data source.

Document new approaches

Crucially, to be able to do the migration for a project,
an operator needs the full configuration available.
It's not terribly difficult if you have it,
but without the data that would be required to do the deployment,
it's impossible to do the migration.

We'll need to create issues to do the per-project migration,
and assign them to someone who can perform them.
To support that,
there's documentation about how that migration works
and how to do that.

Closes hackforla/devops#81