feat(docs): CPLYTM-1191 improve SUBPROJECTS.md

[sonupreetam]

Comprehensive overhaul of SUBPROJECTS.md documentation

Summary

This PR transforms SUBPROJECTS.md from a minimal listing into a comprehensive, well-organized reference document for the entire ComplyTime ecosystem. The document now serves as a single source of truth for understanding all projects under the ComplyTime umbrella.

Key Improvements

Project Lifecycle Status System

Introduced a clear status system to communicate project maturity:

Status	Meaning
🟢 Active	Production-ready, actively maintained
🟡 Incubating	Under development, working toward stability
🔵 Supporting	Foundational/utility, stable but lower cadence
⚪ Archived	Historical reference only

Organized Categories

Projects are now grouped into logical sections:

• Core Projects — Primary user-facing tools (complytime, complyctl, complyscribe, etc.)
• SDKs & Libraries — Foundational libraries (oscal-sdk-go, compliance-to-policy-go, etc.)
• Content & Policies — Compliance content and policy definitions
• Infrastructure & Tooling — CI/CD, templates, and developer tooling
• Community — Governance and contribution docs

Visual Ecosystem Diagram

Added an ASCII diagram showing the relationships between ComplyTime projects

Governance Documentation

Added clear processes for:

• Proposing new subprojects — Criteria, review process, TOC approval
• Archiving subprojects — Conditions and procedures
• Subproject criteria — Alignment, scope, maintainers, licensing

Quick Reference Summary Table

A comprehensive table at the end provides an at-a-glance view of all 21 repositories with their category, status, and description.

Related

• Complements the upcoming CI validation workflow for SUBPROJECTS.md coverage