Add comprehensive README documentation across repository

[Copilot]

Repository lacked READMEs in key directories and existing documentation was outdated without cross-references between components.

Changes

New READMEs (9 added)

• /docs/README.md - Documentation navigation hub
• /terraform/deployments/README.md - Deployment configurations overview
• /terraform/deployments/{home-lab,plex,gh-runner}/README.md - Deployment-specific guides for Kubernetes v1.29 cluster, Plex Media Server, and GitHub Actions runners
• /terraform/modules/README.md - Module development standards and usage
• /terraform/modules/compute/{pm-cloudinit-vm,pve-cloudinit-vm}/README.md - Provider-specific module documentation
• /scripts/deployment/cloud-init/README.md - Comprehensive cloud-init provisioning guide (496 lines)

Updated READMEs (11 modified)

• Root README - Added recent changes section, expanded repository structure with all new docs, quick navigation
• Component READMEs - Added cross-references, related documentation links, consistent structure

Documentation Structure

Each README now includes:

• Directory structure visualization
• Quick start examples
• Configuration reference
• Troubleshooting section
• Cross-references to related docs

Example navigation flow:

Root README → /docs/README.md → /terraform/deployments/home-lab/README.md
                               ↘ /scripts/deployment/cloud-init/README.md

Impact

• 20 total READMEs (from 11)
• 3,278+ lines of documentation added
• Complete deployment guides for all infrastructure components
• Unified cross-reference structure across all documentation

Original prompt

Create a new branch to go through my repo and add READMEs where it makes sense. Then update all readmes with new information since the last time they were updated.

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