###Updated for Grails 2.3.11
Currently only really works for creation of "Command" items and uses a static single.html within snapshots folder
to use a newer version of grails doc you can just open
http://grails.org/doc/latest/guide/single.html in chrome and do file save as... then save it in the snapshots folder as grails_single.html
Still a bit of a work in progress but currently usable.
To build it locally you will need nodejs and grunt...
currently can build by running grunt clean followed by grunt
Still trying to figure out a good way to tie it in with the actual grails doc build as I couldn't get that build locally anyway it may be a little while off...
To use a pre-built version, import grails.docset into Dash.
Forked from: https://github.com/dawogfather/grails-dash-docset
cheers to @gilmoreorless and his https://github.com/gilmoreorless/express-dash-docset for getting me down this path