Zombie villager should drop emeralds

Zombie villagers should have a rare chance of dropping emeralds, just like how normal zombies can drop iron and drowned can drop copper. This would replace their usual chance of dropping iron. Not only does this make sense in terms of the game's lore (zombie villagers used to be villagers, who would have carried emeralds to trade with players and each other), but also allows players to start a superflat world (no structure generation) without a bonus chest (emeralds can be traded with wandering traders for dark oak saplings, providing wood and apples). It's a simple change, yet still impacts the game in many beneficial ways.