Custom Void [Fabric]

Added two new void types, 'Modern' and 'Custom':
* Modern: Renders an ocean-like void like the Classic void type, but with a more desaturated blue to match the modern vanilla water color.
* Custom: Renders a custom void color, modifiable red/green/blue values are available in the config.

If you experience a crash on start-up, please try deleting the old config file and restarting.