chore: simplify README and prepare for npm publish

FINAL PRE-PUBLISH CHANGES:

1. README Simplification:
Before: 300+ lines, complex structure, too much detail upfront
After: 150 lines, crystal clear 3-step quick start

Structure:
- Hero: One sentence + 3-line code block
- Quick Start: 3 numbered steps (install package, install skills, sync)
- Commands: Simple reference table
- What Are Skills: Brief explanation
- Why OpenSkills: Value prop
- Creating Skills: Brief guide with link to docs
- Documentation: Links to detailed guides

Removed from README (moved to docs/):
- Detailed CLI reference
- Full command examples
- Directory structure details
- Claude Code compatibility deep-dive
- Troubleshooting
- Development guide

2. .npmignore Fix:
Now INCLUDES CONTRIBUTING.md and SECURITY.md in npm package
(best practice for transparency)

3. package.json Keywords:
Added: "agents", "progressive-disclosure", "automation", "developer-tools"
Better npm search discoverability

4. Files Included in Package:
- dist/ (compiled CLI)
- examples/ (my-first-skill)
- docs/ (getting-started, creating-skills, integration)
- CONTRIBUTING.md (contributor guidelines)
- SECURITY.md (security policy)
- LICENSE (Apache 2.0)
- README.md (simplified)

Changes:
- README.md: Massive simplification (300→150 lines), 3-step focus
- .npmignore: Include CONTRIBUTING.md, SECURITY.md
- package.json: Added 4 keywords for better discoverability

Validation:
- npm run typecheck: ✅ No errors
- npm run build: ✅ 20.97 KB output
- npm test: ✅ 9/9 tests pass
- prepublishOnly: ✅ Will run typecheck + build + test automatically

READY FOR: npm publish

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Numman Ali

.npmignore

@@ -13,5 +13,3 @@ tsup.config.ts
 vitest.config.ts
 .claude/
 AGENTS.md
-CONTRIBUTING.md
-SECURITY.md