docs: add examples/ (live demo + RESULTS) and slim the README examples

- examples/demo.mjs: live demo (5 single messages up to 5 people with rare
  auto-coined attributes + 5 escalating multi-turn conversations with
  long-range back-references); self-references the package via exports
- examples/RESULTS.md: its generated output (10 examples)
- examples/.env.example + examples/README.md; `npm run example` script
- README: replace the long examples section with two representative examples
  (dense 5-person message + 6-turn conversation) and a badge/link to
  examples/RESULTS.md for the full set
- eslint ignores examples/**, prettier ignores generated examples/RESULTS.md,
  .gitignore un-ignores .env.example

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -44,6 +44,7 @@
   },
   "scripts": {
     "build": "tsup",
+    "example": "npm run build && node --env-file=examples/.env examples/demo.mjs",
     "test": "vitest run",
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",