Fix minor typos on README
Fix minor typos on README

ysb33r/asciidoctor-gradle-plugin,asciidoctor/asciidoctor-gradle-plugin,ysb33r/asciidoctor-gradle-plugin,asciidoctor/asciidoctor-gradle-plugin,ysb33r/asciidoctor-gradle-plugin,asciidoctor/asciidoctor-gradle-plugin,ysb33r/asciidoctor-gradle-plugin,asciidoctor/asciidoctor-gradle-plugin,asciidoctor/asciidoctor-gradle-plugin,ysb33r/asciidoctor-gradle-plugin