This (I think) was originally a ROM port, that Desden ported to Smaug, and now is ported to AFKMud.
It sets up a new act flag for mobs, "healer", which allows players to buy healing from the mob.
As far as configuration goes, it's a hand editing job of the gold charged for each healing spell, changing the price list as well. Since I have absolutely no idea how to actually write C, I have no chance of making this easy to tweak, sorry
To make it easier, I've moved the instructions to here.