ci: call 'make htmldocs' from root

            echo "Building a Pull Request";

            echo "- Building Documentation";

            echo "Commit range:" ${COMMIT_RANGE}

            pushd doc

            make htmldocs > doc.warnings 2>&1;

            if [ -s doc.warnings ]; then

              echo " => New documentation warnings/errors";

            fi;

            popd

            echo "- Verify commit message, coding style, doc build";

            ./scripts/ci/check-compliance.py --commits ${COMMIT_RANGE} || true;

          fi;