Migrate User Guide and Release Notes to Antora

[marcphilipp]

• Adjust headings in generated API reports
• Set up Antora module
• Add task to build Antora site locally
• Extract conventions plugin
• Update README to reference Antora
• Remove Asciidoctor plugins
• Remove git-publish plugin and corresponding GitHub Action steps
• Move images to Antora module
• Migrate link attributes to antora.yml
• Remove Asciidoctor User Guide main document
• Move overview.adoc to Antora module
• Migrate overview.adoc to Antora syntax
• Add overview.adoc to navigation
• Move writing-tests.adoc to Antora module
• Migrate writing-tests.adoc sections to Antora
• Migrate writing-tests sections to Antora syntax
• Add writing-tests sections to navigation
• Move migrating-from-junit4.adoc to Antora module
• Migrate migrating-from-junit4.adoc to Antora syntax
• Add migrating-from-junit4.adoc to navigation
• Move running-tests.adoc to Antora module
• Migrate running-tests.adoc sections to Antora
• Migrate running-tests sections to Antora syntax
• Add running-tests sections to navigation
• Move extensions.adoc to Antora module
• Migrate extensions.adoc sections to Antora
• Migrate extensions sections to Antora syntax
• Add extensions sections to navigation
• Remove Advanced Topics include file
• Move junit-platform-reporting.adoc to Antora module
• Migrate junit-platform-reporting.adoc to Antora syntax
• Move junit-platform-suite-engine.adoc to Antora module
• Migrate junit-platform-suite-engine.adoc to Antora syntax
• Move testkit.adoc to Antora module
• Migrate testkit.adoc to Antora syntax
• Move launcher-api.adoc to Antora module
• Migrate launcher-api.adoc to Antora syntax
• Move engines.adoc to Antora module
• Migrate engines.adoc to Antora syntax
• Add advanced topics to navigation
• Move api-evolution.adoc to Antora module
• Migrate api-evolution.adoc to Antora syntax
• Add api-evolution.adoc to navigation
• Remove Contributors link to GitHub
• Move release-notes.adoc to Antora module
• Migrate release-notes.adoc to Antora syntax
• Add release-notes.adoc to navigation
• Move individual release note files to Antora module
• Move release-notes-TEMPLATE.adoc to Antora module
• Migrate release-notes-TEMPLATE.adoc to Antora syntax
• Move appendix.adoc to Antora module
• Migrate appendix.adoc to Antora syntax
• Add appendix.adoc to navigation
• Fix links
• Remove obsolete Asciidoctor resources

[testlens-app]

✅ All tests passed ✅

🏷️ Commit: 3e4bbf7
▶️ Tests: 490 executed
⚪️ Checks: 16/16 completed