Add automatic documentation generation from homelab-summary module output

[badele]

Description
Implement automatic documentation generation using files produced by the homelab-summary module (currently in development).

Motivation
Manual documentation maintenance is time-consuming and prone to becoming outdated. The homelab-summary module generates structured data about the homelab configuration, which can be automatically transformed into comprehensive, always up-to-date documentation.

Proposed Solution
Create a workflow that:

1. Extracts data from homelab-summary module outputs
2. Generates documentation in a human-readable format (Markdown, HTML, or both)
3. Updates documentation automatically when configurations change
4. Optionally publishes documentation to GitHub Pages or similar platform

Acceptance Criteria

• Documentation is automatically generated from homelab-summary output
• Documentation includes key information: services, hosts, network topology, etc.
• Documentation is regenerated when Nix configurations change
• Generated docs are committed to repository or published to docs platform
• Documentation format is clear and easy to navigate
• Process is fully automated (no manual intervention required)

Additional Notes

• Wait for homelab-summary module to reach a stable state before implementation
• Consider documentation format: plain Markdown, MkDocs, mdBook, or GitHub Pages
• May want to include diagrams (network topology, service dependencies) using tools like Mermaid or Graphviz
• Should handle incremental updates efficiently (only regenerate changed sections)
• Consider adding a preview mechanism for documentation changes in PRs