Merge pull request #13 from johncarl81/master

Synced readme with Asciidoctor docs
fix groupId in example maven configuration

The example maven configuration snippet uses 'org.asciidoc' as the groupid, instead of 'org.asciidoctor'.
Merge pull request #14 from mattdrees/patch-1

fix groupId in example maven configuration
Merge branch 'master' of github.com:asciidoctor/asciidoclet
Upgraded to latest asciidoctor-java-integration