Add boxen module maker

Add a note about a gem I've recently made to make it easier to create boxen puppet modules

Also update the .gitignore, as I accidentally uploaded the stdlib module from specs in a recent project.

BTW is there a `boxen` google group or mailing list? Would be cool to have a place were people can ask for help with boxen or get people to review modules they've made. I might make one if that's ok? :+1: