Well... I'll keep my eyes open, but if you didn't find anything on Ravelry I'm not sure there is one.
I did a search on dress/newborn and free and there wasn't a lot of choice.
You only want a dress? Newborns generally don't wear many dress up type clothes... mine pretty much stayed in sleepers or romper type clothing. Now if you want a sweater you'll have all kinds of choices.