Abridged is back!

• Updated the mod to Fabric/Neoforge 1.21.1 and 1.21.7, while maintaining support for Fabric/Forge 1.20.1.
• Added bridges over valleys that cross both land and water.
• Added two new bridge variants: Fancy Oak and Tuff. Tuff is only present on 1.21.x.
• Overhauled the bridge spawning system internals. Locating bridges should be significantly faster now.
• Added the ability to add new bridge variants with a datapack, tutorial soon™️.