Dungeons are dynamically registered based on the files located at .minecraft/Chocolate/DungeonConfig. Each file containing a valid "builder" will be registered as a dungeon.
To specify a builder just write "builder = builderName", there are many different builders (premade buildings, procedural dungeons/caves).
There are other properties to configure the dungeons, some properties are present in all dungeons, and other properties are depending on the builder.
biomes = Plains, Desert
A list of biomes to spawn the dungeon, separated by ",".
chance = 10
Define the ratio at wich the dungeon spawns. The formula goes like that: every 5 (or the number specified as chunk separation in the main config file)chunks, there is 1 between the number set to chance probabilities to spawn a dungeon.
mob = default
This line defines the mob to be spawned on the spawners of this dungeon. Points to a mob register that provides mele, ranged, special and boss entities of the type specified. Valid mobs are: default(diferent mobs based on distance to spawn), skeleton, goblinGreen, goblinBlue, zombie, gremlin, specter, minotaur, golem, walker, dwarf, pirate, pigman, monkey, triton, ogre.
icon = 0
Is used for the spawning item.