Changes

Enable dependabot for dependencies

Bump org.asciidoctor:asciidoctorj from 2.5.10 to 2.5.13

Bumps [org.asciidoctor:asciidoctorj](https://github.com/asciidoctor/asciidoctorj) from 2.5.10 to 2.5.13.
- [Release notes](https://github.com/asciidoctor/asciidoctorj/releases)
- [Changelog](https://github.com/asciidoctor/asciidoctorj/blob/v2.5.13/CHANGELOG.adoc)
- [Commits](https://github.com/asciidoctor/asciidoctorj/compare/v2.5.10...v2.5.13)

---
updated-dependencies:
- dependency-name: org.asciidoctor:asciidoctorj
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>