feat: rename config dir to ~/.config/beepctl/ with auto-migration

- Changed config path from beepcli to beepctl
- Auto-migrate existing config on first run (copies + removes old dir)
- Updated README with complete documentation for all commands
- Updated CONTRIBUTING.md references
- Bump version to 0.1.3

chore: add badges, fix CI, update changelog

- Add npm version and CI badges to README
- Fix CI workflow pnpm version conflict
- Add 0.1.1 to CHANGELOG