feat(skills): add wellarchitected.github.com content to iac-terraform-modules-eng

[aRustyDev]

Summary

Add references and patterns from https://wellarchitected.github.com to the iac-terraform-modules-eng skill.

Rationale

The GitHub Well-Architected framework provides best practices for repository structure, CI/CD, and collaboration patterns that complement Terraform module development. Currently, this skill references AWS/Azure Well-Architected Frameworks but not the GitHub-specific framework.

Scope

• Add wellarchitected.github.com as a reference alongside existing AWS/Azure Well-Architected references
• Incorporate GitHub-specific patterns for module repository structure
• Add guidance on module CI/CD, testing workflows, and release automation per the framework

Related Skills

This is part of a broader effort to add wellarchitected.github.com content to:

• cicd-github-actions-dev
• cicd-github-actions-ops
• github-actions-dev
• github-app-dev
• iac-terraform-modules-eng (this issue)
• iac-terraform-orchestration-ops