[DEMOCODE675]

Summary

Improve the project README and document the recommended repository description.

What changed

• Replaced the minimal README with a complete user and contributor guide.
• Documented installation, quick start, command reference, supported ecosystems, plugin architecture, and development checks.
• Added CI and Python badges.
• Proposed repository description: Cross-platform CLI that clones GitHub repositories, detects their stack, installs dependencies, and runs health checks through an extensible plugin system.

Verification

• Documentation-only change; no code tests required.

Notes

• Direct repository metadata updates were unavailable to this session, so the description is included here for a maintainer to apply.