.groupy spec and/or hook support

Hey there,

I'm a software dev who just got a humongous monitor and is finding Groupy exceedingly useful for keeping stuff organized.

I took a look at a `.groupy` file, and `NoPatternMatching=0` stood out to me - maybe _I_ could do some matching?

My end goal here would be to hook something when creating/entering a group to change the title of the grouped item, e.g.

`function onGrouped(groupName, groupedItem) => groupedItem.Title = 'something'`

Is something like this feasible?

Thanks so much for the handy tools,

- Dave Beiler

edit because I'm used to markdown not bbedit