Issues status review

[abelsromero]

I went throw 2 first pages of issues and I found the following that can be probably closed:

• Already done

  • Rename main branch Rename master branch #930
  • Java 14 support: Update Gradle so that build can run with Java 14 #921
  • Support source highlighter Add support for source highlighters implemented in Java #805

• Questions/not relevant/not answered:
  Can we select a specific table using the selector.put ? #912
  asccidoctorj logs multiple "possible invalid reference" #901
  Update rubygems-proxy to official URL #896
  Updating from 1.5.3 to 2.2.0 breaks #886
  AST Builders should be part of AST package #881
  asciidoctorj-pdf error when processing #857
  Regression in 2.1.0: Asciidoctor.Factory.create() produces a "java.util.ServiceConfigurationError" #832
  [CLI] java.lang.ClassNotFoundException: org.asciidoctor.cli.AsciidoctorInvoker #831
  Make -R the default in the CLI #828
  Undiscoverable CLI version #827
  problem with uber jar #820
  IncludeProcessor: clarification of PreprocessorReader.push_include(..) #800
  asciidoctor sbt plugin #781
  Render methods should be marked deprecated #730
  Trouble accessing attributes #728
  1.6.0-RC.1: isBlock() always return true #726
  Binary incompatible changes in 1.6 #697
  Remove the StructuredDocument AST from AsciidoctorJ 1.6 #694

Also, these could tagged as Upstream:
#946
#899
#895 (just reproduced in Win10)

[abelsromero]

I plan to keep reviewing in the following days :$