Added pointer to AsciidoctorJ 1.6.0 for users of the extension API
Added pointer to AsciidoctorJ 1.6.0 for users of the extension API

abelsromero/asciidoctorj,ysb33r/asciidoctorj,ysb33r/asciidoctorj,asciidoctor/asciidoctorj,lefou/asciidoctorj,abelsromero/asciidoctorj,lefou/asciidoctorj,robertpanzer/asciidoctorj,ysb33r/asciidoctorj,robertpanzer/asciidoctorj,ysb33r/asciidoctorj,robertpanzer/asciidoctorj,abelsromero/asciidoctorj,asciidoctor/asciidoctorj,lefou/asciidoctorj,asciidoctor/asciidoctorj,lefou/asciidoctorj