Improve README with quick start examples and badges

[azrollin]

The README needs:

• Badges (PyPI version, license, tests passing, Python versions)
• Quick "Try it in 2 minutes" section with copy-paste examples
• GIF or screenshot showing a scan in action
• Architecture overview diagram

Any of these individually would be a great first contribution.

[azrollin]

Update (v0.2.3, April 4, 2026):

Progress check against the original checklist:

• Badges — Still needed. PyPI version, license (AGPL-3.0), tests passing, Python versions badges not yet added to the top of README.
• Quick Start section — ✅ Added! Full CLI examples including install, scan, file scan, deep scan, JSON output, stdin pipe, and demo command.
• Integration examples — ✅ Added! Python API code samples for both SunglassesEngine (text) and SunglassesScanner (media).
• GIF/screenshot — Still needed. A terminal recording showing a scan catching an attack would be great.
• Architecture diagram — Still needed.

Also needs updating in README:

• Performance table still shows v0.1.0 numbers (53 patterns, 334 keywords, 12 categories) — actual is 75 patterns, 442 keywords, 18 categories
• "What Works Today" section still says v0.1.0

Remaining work — great first contributions:

• Add badges to the top of README (PyPI, license, tests, Python 3.8+)
• Record a terminal GIF with asciinema or terminalizer
• Create a simple architecture diagram (Mermaid or ASCII art)
• Update the stats to reflect v0.2.3 numbers

Any of these individually is a solid first PR. 🕶️