Add guide - Stack Drift Detection

[johnsmyth]

Guide purpose
Write a guide to managing stack drift detection in the Guides / Using Guardrails / Stacks section.

Target audience
Anyone who wants to deploy stacks. You can assume a working knowledge of terraform.

Categories
stacks, networking

Outline

Step through managing stack drift detection. . The doc should walk through installing the policy pack, setting policies, attaching, running, and verifying. Discuss the various drift detection option when setting the policies. Use theDeploy AWS IAM Stack policy pack as we use in the Deploy a Stack and Destroy a Stack guides - It already has the policies in the policies.tf file, commented out