Datical, the company that I work for is adding more resources to support Liquibase. One of the things that we would like to do is improve the dbDoc command, so your addition would be very welcomed.
The dbDoc stuff was designed quite a long time ago and hasn't been an area where people have asked for very many fixes/changes/additions. I am not super-familar with that part of the code, so I'm not sure of the best way to extend it. A quick look and it seems like you might be able to add a new method to DBDocVisitor named 'writeAsciiDoc' or similar, and then in the Liquibase class, in the generateDocumentation method, have it call that method instead of the writeHTML method.
What would be even better would be to spend some more time in those classes and come up with an interface and make it a pluggable extensible thing. I'll check with Nathan and see what his thoughts are.
Steve Donie
Principal Software Engineer
Steve Donie
Principal Software Engineer
Liquibase Community Engagement
Datical, Inc. http://www.datical.com/
Datical, Inc. http://www.datical.com/