chore: add CONTRIBUTING.md

Author: adriencaccia

CONTRIBUTING.md

@@ -0,0 +1,32 @@
+# Contributing
+
+## Releasing a New Version
+
+To create a new version, run:
+
+```bash
+uvx bumpver update --patch  # Increment PATCH component (e.g., 1.2.3 -> 1.2.4)
+uvx bumpver update --minor  # Increment MINOR component (e.g., 1.2.3 -> 1.3.0)
+uvx bumpver update --major  # Increment MAJOR component (e.g., 1.2.3 -> 2.0.0)
+```
+
+### What happens
+
+1. **Pre-release script** (`scripts/pre-release.sh`):
+   - Generates the changelog using `git cliff` (skipped for alpha/beta/rc releases)
+   - Updates `uv.lock`
+
+2. **Version bump**:
+   - Updates the version in `pyproject.toml` and `src/pytest_codspeed/__init__.py`
+   - Creates a commit with the message "Release vX.Y.Z"
+
+3. **Post-release script** (`scripts/post-release.sh`):
+   - Creates a git tag with the `v` prefix (e.g., `v1.2.3`)
+   - Pushes the commit and tag to the remote
+
+4. **CI release workflow** (`.github/workflows/release.yml`):
+   - Triggered automatically when the tag is pushed
+   - Builds wheels for x86_64 and aarch64
+   - Builds the source distribution
+   - Publishes the package to PyPI
+   - Creates a draft GitHub release