FR: add architecture documents

[obriensystems]

TL;DR

Expand on the architecture sections in the root and folder readme's https://github.com/terraform-google-modules/terraform-example-foundation?tab=readme-ov-file#terraform-example-foundation

Reference where possible the security foundations architecture that references this TEF repo https://cloud.google.com/architecture/security-foundations

Reference applied terraform-google-modules and their architecture subset for example the project factory https://github.com/terraform-google-modules/terraform-google-project-factory

Ill do a first pass on the default architecture during a reverse engineering of the code - towards the following purposes

• extensibility
• customer deployment documentation
• architecture discussions/modification
• High Value and protected deployments around NIST-800-53, ITSG-33 and FedRAMP

Terraform Resources

No response

Detailed design

Architectural examples include

• https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/wiki/Architecture
• https://github.com/GoogleCloudPlatform/pubsec-declarative-toolkit/blob/dev/solutions/landing-zone/architecture.md
• https://github.com/ssc-spc-ccoe-cei/gcp-documentation/blob/main/Architecture/Repository%20Structure.md
• https://github.com/GoogleCloudPlatform/pbmm-on-gcp-onboarding/blob/main/docs/architecture.md
• https://github.com/Azure/CanadaPubSecALZ/blob/main/docs/architecture.md
• https://aws-samples.github.io/aws-secure-environment-accelerator/latest/architectures/sensitive/
• https://github.com/aws-samples/landing-zone-accelerator-on-aws-for-cccs-medium/tree/main/architecture-doc
• https://github.com/oracle-quickstart/oci-cis-landingzone-quickstart/blob/main/cis-architecture-mapping.md
• https://cloud.google.com/docs/terraform/iac-overview

Include bidirectional links between this repo and TEF references in

• https://cloud.google.com/docs/terraform/blueprints/terraform-blueprints
• https://cloud.google.com/architecture/security-foundations

Additional information

• see #1178

No response

[fmichaelobrien]

stale bot timer restart - https://github.com/terraform-google-modules/terraform-example-foundation/blob/master/.github/workflows/stale.yml#L21