Items/Blocks Spawn in Villages and Dungeons

Hello,

I would like that items of my mods can spawn in chest of Villages and Dungeons (spawners and chests). So, can you add this possibility because I know that you can add this because a lot of mods have this features.

Thanks you by advance,

Goldorion

P-S : I am very impatient for MCreator 1.8.3. ;)