Remove redundant setup.py and document version update process

README.md

@@ -1,2 +1,51 @@
 # umep-reqs
 A minimal Python package outlining UMEP dependencies.
+
+## Installation
+
+```bash
+pip install umep-reqs
+```
+
+## Version Management
+
+This package uses `setuptools_scm` for automatic versioning based on Git tags. The package version is automatically determined from the latest Git tag.
+
+### How to Update Dependencies
+
+When a new version of SuPy or other dependencies is released:
+
+1. **Update the dependency version** in `pyproject.toml`:
+   ```toml
+   dependencies = [
+       "supy==2025.6.2.dev0",  # Update this version number
+       "numba==0.59.0",
+       # ... other dependencies
+   ]
+   ```
+
+2. **Commit your changes**:
+   ```bash
+   git add pyproject.toml
+   git commit -m "Update SuPy to version X.X.X"
+   ```
+
+3. **Create a new release tag**:
+   ```bash
+   git tag 2.6  # Use the next version number
+   git push origin main
+   git push origin 2.6
+   ```
+
+4. **The CI/CD pipeline will automatically**:
+   - Build the package with the new dependencies
+   - Publish to Test PyPI (for all pushes)
+   - Publish to PyPI (for tagged releases)
+   - Create a GitHub release
+
+### Important Notes
+
+- **DO NOT** manually update version numbers in code - they are managed by Git tags
+- All dependency updates should be made in `pyproject.toml`
+- The `setup.py` file has been removed in favour of modern `pyproject.toml` configuration
+- Version numbers follow semantic versioning (MAJOR.MINOR.PATCH)