Welcome to the advancement tutorial!

Please follow the conventions here! Please. I only have so much sanity.

So!
Advancement trees for elements are defined as such:
Scroll Find > Element Unlock > Ranks > Abilities.
    Abilities have 2 advancements: unlocking, and maxing. Maxing should be a 'challenge', basic abilities should be a
    'task', and everything else is a goal.
    If you're confused about how advancements work, check out this tutorial here: https://www.minecraftforum.net/forums/minecraft-java-edition/redstone-discussion-and/commands-command-blocks-and/2809368-1-12-custom-advancements-aka-achievements#Requirements

Conventions for this mod???
    Each ability maxing advancement should have 4 triggers, and they'll only require 1. This accounts for levels 3>4,
    2>4, 1>4, and 0>4. Each bending rank should give access to its appropriate tiers scrolls. For example:
    Novice:
        Tiers 1-2.
    Nomad:
        Tier 3
    Monk:
        Tier 4
    Gyatso:
        Tiers 5-6
    Siddhartha:
        Tier 7.
    Additionally, relevant elemental items should be given. E.g., water pouch recipes should be given after obtaining a water scroll.
    The basic glider should be given at Nomad rank, while the advanced should be given at Gyatso.

Examples?
    Checkout airbending! It should give you a good idea of what to expect. Don't worry if recipes don't work, I'll handle those.
    Just report them to me.

Anything else?
    Be sure to include appropriate xp amounts!