Effect Gems

Updated to Minecraft 1.21.5
Datapack now works on the latest version of Minecraft

Added Gem Dual-Wielding
Effect Gems now also work when held in the mainhand Players can get the buffs of two gems at once
Effects will not stack if the same gem is held in both hands

Added Crown Armor Item
Now, instead of using a custom player head, the Gem Zombie uses a custom crown armor item
The armor item has 3 armor, but a measly 90 durability
The item has a 10% chance to drop from any given Gem Zombie
Item is not worn by the Gamingbarn's Zombies Gem Zombie

Buffed GBZ Variant of Gem Zombie
GBZ Gem Zombie now spawns with higher armor and higher movement speed
The GBZ Gem Zombie now fits in more with the other GBZ Zombies

Optimized datapack
Less code runs less frequently than before