Four Elemental Swords

First version for Minecraft 26.1.2

Added
- On-hit effects: Air gives Levitation, Earth gives Slowness, Water gives Weakness (Fire still sets enemies on fire).
- Optional cooldown and durability cost for the right-click ability.
- Two new config files: `elemental-swords-abilities.toml` and `elemental-swords-hit-effects.toml`.
- Recipes now unlock in the recipe book.

Fixed
- Attack speed in the config was ignored.
- Swords lost 2 durability per hit instead of 1.