Release version 2.0.0

[abelsromero]

This PR is to decide the changes and steps for the release of version 2.0.0 aligned with last AsciidoctorJ (currently v2.2.0).

I think the next things need to be done for the next release:

• Update of AsciidoctorJ dependency (and derivated changes) -> (PR Upgrade to asciidoctorj 2 2 0 #24)
• Fixes in documentation (as mentioned in Some example in README don't match implementation #14 (comment)) -> (PR Improved examples and format of README #28)
• Removal of deprecated methods. This is the moment, we are moving to a major version. -> (PR remove deprecated methods #27)
• Build compatibilty with Java 11. Current version of Gradle only works with Java 8. -> (PR fix/make build compatible with java11 #25)
• Start a CHANGELOG.adoc -> (PR Add Github Actions, Changelog and PR template #26)

Anything else I am missing @robertpanzer?

[robertpanzer]

That sounds great!

[robertpanzer]

Agreed, let's remove the deprecated methods.

[abelsromero]

All is ready. Let me know if you see anything you want me to change in some way.