Update Usage docs

[abelsromero]

• Update Antora properties for v2.0.0
• Update usage with Maven Java 11 and 17+ examples
• Update usage with Gradle Java 11 and 17+ examples
• Remove Ant example. Given my experience trying to get it to work, I cannot recommend it. Most examples online don't work and are years old. Even if only for Javadoc I'd suggest anyone to set up Maven or Gradle nowadays.
• Update ITs to align with the examples.
• Replace incorrect "Asciidoc" mentioned by "AsciiDoc" in docs

Closes #127

[abelsromero]

@dakusui I'd appreciate if you could have a look at the updated examples 🙏 I tested several times and the ITs (with maven-invoker-plugin) are green in the GitHub actions. But I found it odd that Java 11 only requires 1 "exports", can you confirm this from your side?

[dakusui]

Alright.
I'll do it today or tomorrow.

[abelsromero]

No rush really

[dakusui]

Both of them seem to work.

• Java 11: https://github.com/dakusui/java-17-21-template/tree/java11-trial
• Java 21: https://github.com/dakusui/java-17-21-template/tree/java21-trial

Please check the elements in pom.xmls and image.pngs at the top directory.
I only needed to change the version string to meet maven's usual convention.

[abelsromero]

Thanks! I'll have a final triple-check and if all is well (which seems), merge and start thinking about the release.