Release v0.3.1

[duriantaco]

Summary

• Bump package version from 0.3.0 to 0.3.1
• Move the raw scalar output changelog entry into the v0.3.1 release section

Release notes

• Adds -r, --raw, and --raw-output for unquoted scalar output in shell pipelines
• Example: jonq users.json "select name" -r

Verification

• pytest -q
• uvx ruff check --force-exclude jonq tests
• python -m compileall -q jonq
• python -m build
• python -m twine check dist/*
• python -m jonq --version
• python -m pre_commit run --all-files
• python -m pre_commit run --hook-stage pre-push --all-files