Refs #1

Summary

• add bash changelog.sh to generate a structured CHANGELOG.md from commits since the latest tag
• add a /generate-changelog Claude command plus a skills/generate-changelog wrapper
• include a 3-step setup README, sample output from this repo, and a regression test

Acceptance criteria covered

• supports bash changelog.sh and /generate-changelog
• fetches commits since the latest git tag, or all commits when no tag exists
• categorizes entries into Added, Fixed, Changed, and Removed
• writes formatted changelog output to CHANGELOG.md
• includes sample output in examples/claude-builders-bounty-sample.md
• keeps setup instructions to 3 steps in docs/changelog-generator/README.md

Validation

• git diff --cached --check
• bash -n changelog.sh && bash -n tests/test-changelog.sh
• bash tests/test-changelog.sh
• bash changelog.sh --output examples/claude-builders-bounty-sample.md