src/site/build.gradle

apply plugin: 'org.asciidoctor.gradle.asciidoctor'

buildscript {
  repositories {
    jcenter()
  }
  dependencies {
    classpath 'org.asciidoctor:asciidoctor-gradle-plugin:1.5.0'
  }
}

asciidoctor {
  sourceDir = new File("site-docs")
  outputDir = new File("site-build")
  options = [
      doctype: 'book',
      attributes: [
          'source-highlighter': 'coderay',
          toc                 : '',
          idprefix            : '',
          idseparator         : '-'
      ]
  ]
}