Restructure README for better user onboarding and feature discovery:

- Add crates.io, docs.rs, license, and MSRV badges
- Frame the problem/solution with concrete examples
- Convert linear feature list to organized feature table
- Improve quick start flow with composable attribute examples
- Add tables for metrics, verification, and configuration sections
- Expand examples section with per-feature demo references
- Simplify CLI reference (point to --help for full options)
- Maintain technical accuracy while improving accessibility