iab advancements pack

adds small things to make the game easier and harder.

The "IAB Advancement Pack" is a mod designed to enrich gameplay through new items, blocks, entities, and advancements. Here's a detailed overview:

Advancements:
- Welcomeadv & Greatenhanceadv: These are likely tied to introductory and milestone achievements within the mod, guiding players through its content.
- Iab: Represents the core advancement or theme of the mod, tying all elements together.
Items & Blocks:
- Skullbag: An item with special effects when used, potentially tied to advancement or gameplay mechanics.
- Purification Powder: A mystical item that purifies or transforms entities or blocks, with a specific recipe (Purepowdrecipe) and interactions while in the player's inventory (PurificationpowderItemInInventoryTick).
- Copper Tools: A set of copper-based tools (Pickaxe, Axe, Sword, Shovel, Hoe) that offer an alternative material for crafting, with their respective recipes.
- Happystone: A block that plays a role in the mod, potentially providing positive effects when destroyed.
Entities & Mobs:
- Poison Ivy: A dangerous plant that interacts with players (PoisonivyMobplayerCollidesWithPlant), likely causing damage or debuffs.
- Mad Cow: A hostile or neutral mob that drops specific items (Madcowdrops), adding to the game's challenge.
- Ivy Creeper: A variant of the Creeper, potentially tied to the Poison Ivy or other environmental hazards.
Miscellaneous:
- Test: Possibly a placeholder or test element within the mod.
- Purebeef: An item likely dropped by the Mad Cow, purified or enhanced by the Purification Powder.