chore: add CONTRIBUTING.md

Author: ahal

CONTRIBUTING.md

@@ -0,0 +1,39 @@
+# Contributing
+
+## Development
+
+Install dependencies with [uv](https://docs.astral.sh/uv/getting-started/installation/):
+
+    uv sync
+
+Run tests:
+
+    uv run pytest
+
+Run linters:
+
+    uv run commit pre-commit run -a
+
+Install the pre-commit hooks (runs automatically on each commit):
+
+    uv run pre-commit install --hook-type commit-msg
+
+Commits must follow the [Conventional Commits](https://www.conventionalcommits.org/) format,
+e.g. `feat: add new command` or `fix: handle missing config file`. This is enforced by the
+pre-commit hook above.
+
+## Releasing
+
+1. Run `cz bump` to update the version and changelog:
+
+       uv run cz bump
+
+   This will increment the version in `pyproject.toml` based on the commit history since the
+   last release, append the new section to `CHANGELOG.md`, and create a git tag.
+
+2. Push the commit and tag:
+
+       git push origin master --tags
+
+3. Create a GitHub release for the new tag. The `pypi-publish` workflow will automatically
+   build and publish the package to PyPI when the release is published.