Add contribution guide

Author: njoguamos

CONTRIBUTING.md

@@ -0,0 +1,33 @@
+# Contributing
+
+## Development Setup
+
+1. Fork and clone the repository.
+2. Create a virtual environment.
+3. Install the project in editable mode.
+
+```bash
+python3 -m venv .venv
+source .venv/bin/activate
+python -m pip install -e .
+```
+
+## Running Tests
+
+Run the test suite before opening a pull request.
+
+```bash
+python -m unittest discover -s tests
+```
+
+## Pull Requests
+
+1. Keep changes focused and minimal.
+2. Add or update tests when behavior changes.
+3. Update documentation when user-facing behavior changes.
+4. Open a pull request with a clear description of the change.
+
+## Notes
+
+- CI runs automatically for pull requests.
+- Markdown-only changes do not trigger the test workflow.

README.md

@@ -199,6 +199,7 @@ PYTHONPATH=src python3 -m jenga.cli account-balance --country-code KE --account-
 - This package currently focuses on a small subset of Jenga APIs.
 - The README only documents endpoints that are actually implemented in this repository.
 - Pending endpoints are listed for roadmap visibility only.
+- See the [contribution guide](./CONTRIBUTING.md) for development and pull request workflow.
 
 ## 7. License
 License: [MIT](./LICENSE)