Upgrade & refactor asciidoctor-maven-plugin config

[abelsromero]

• Bump asciidoctor-maven-plugin to v2.2.2
• Bump AsciidoctorJ to v2.5.6
• Bump AsciidoctorJ PDF to v2.1.6
• Refactor configuration
  • To remove duplication
    • Added Maven properties for shared versions and paths.
    • Use common in plugins for all executions.
  • Removed unused elements
    • imagesdir attribute in html already uses default value.
    • imagesdir in pdf no longer requires to point to target (issue fixed in upstream).
  • Created single executions to convert only required files: index, toc, release-notes.
    This has the advantatge that displays errors/warning for each file as independent
    steps during maven build.
• Other changes
  • Set source-highlighter in PDF to rouge which is current recommended.
  • Set outputFile to 'reference.pdf' for convenience.

[abelsromero]

Build shows several errors for toc.adoc that now are easier to spot and fix. I can tackle those in another PR if this is fine.

mvn clean generate-resources -P generate-html -pl asciidoc -am

----
[INFO] --- asciidoctor-maven-plugin:2.2.2:process-asciidoc (generate-toc-html) @ asciidoc ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 3 resources
[INFO] asciidoctor: WARN: distributed/jdbc/jdbc-integraions.adoc: line 19: section title out of sequence: expected level 3, got level 4
[INFO] asciidoctor: WARN: distributed/jdbc/jdbc-integraions.adoc: line 48: section title out of sequence: expected level 3, got level 4
[INFO] asciidoctor: WARN: distributed/jdbc/jdbc-integraions.adoc: line 48: id assigned to section already in use: listener
[INFO] asciidoctor: WARN: advanced/listener.adoc: line 2: id assigned to section already in use: listener
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-proportionally
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-as-is
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-additive
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-proportionally
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-as-is
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-additive
[INFO] asciidoctor: INFO: possible invalid reference: tokens-inheritance-strategy-as-is
[INFO] Converted /home/asalgadr/github/bucket4j/asciidoc/src/main/docs/asciidoc/toc.adoc
----

[vladimir-bukhtoyarov]

Hello @abelsromero

Thank you, all looks good, excepting that for profile generate-html-plain does not work now, because index.html and release-notes.html are empty now. This profile is used each time when I do release to generate files:

• https://github.com/bucket4j/bucket4j.github.io/blob/master/8.0.1/release-notes.html that looks as https://bucket4j.com/8.0.1/release-notes.html
• https://github.com/bucket4j/bucket4j.github.io/blob/master/index.html that looks as https://bucket4j.com/
  In other words this profile is used to generate documentation files without table of contents.

I have merged this request the to the branch try_new_asciidoctor please use it for next requests related to asciidoctor migration. If you know how to fix generate-html-plain it will be nice to provide correspondent pull-request.

[abelsromero]

I have merged this request the to the branch try_new_asciidoctor please use it for next requests related to asciidoctor migration

Excellent idea 👍

Thank you, all looks good, excepting that for profile generate-html-plain does not work now, because index.html and release-notes.html are empty now. This profile is used each time when I do release to generate files:

Found it, doctype must be Inline in uppercase. In fact I think we can remove the use of doctype, it does not apply if we are building a single page HTML document(s).

This profile is used each time when I do release to generate files:

If I understand correctly, for a release the process would be:

• Generate toc.html with generate-html
• Generate index.html & release-notes.html with generate-html-plain
• Manually copy and place those files under proper path: index in the root path and the other two under the version directory.

If that's the case, we can just setup a single profile "generate-html-docs" that does exactly that. Leaving index in the directory above the version one.
Also keep the PDF which I guess is a nice-to-have but is not being used to publish any content.

[vladimir-bukhtoyarov]

Yes, you correctly understand release process, I do not have objections to merge html generation in one profile.

[vladimir-bukhtoyarov]

Thank you very much. Has been merged to master.