CONTRIBUTING.md

Applying api changes

1. navigate to the subproject(s) matching the api version(s) to be changed
2. update the docker-engine-api-v<VERSION>.yaml
3. execute in the project's root directory: ./gradlew :api-model-v<VERSION>:updateApiModelSources
4. verify the code changes, e.g. using git status or git diff
5. perform checks: ./gradlew check
6. push the changes to your fork and submit a pull request (see GitHub's documentation for help about contributing to a project)