Document Per-Environment Configuration Setup

[devorekristen]

What is it?

Create documentation at /docs/environments.md that explains how to configure and deploy this template in a Dev/Test/Prod environment setup, including environment-specific variables, state handling, and promotion best practices.

Definition of Done

• Written guide or markdown in docs/environments.md
• Includes at least one usage example per environment
• Mentions tooling or workflow assumptions (e.g., GitHub Actions, Terraform Cloud, etc.)

Value Provided

Helps teams adopt the pattern correctly and consistently across environments.

Part of #22