Fix crash on version 1.20

[jbazant]

Fixes #75.

Proposed Changes

• fixed access to unitialized BIOMES item
• Small refactoring of relevant code

[RedstoneFuture]

The PR works well on my server. Thanks!

Tested with PaperMC 1.20.4 (build 409) and Dynmap v. 3.7-beta-4-935

[Pezmc]

For those less technically minded, I've built a release jar which includes this change (thanks go to @jbazant) and some version upgrades, and can be downloaded at https://github.com/Pezmc/dynmap-structures/releases/tag/2.6.2

[UplandJacob]

For those less technically minded, I've built a release jar which includes this change (thanks go to @jbazant) and some version upgrades, and can be downloaded at https://github.com/Pezmc/dynmap-structures/releases/tag/2.6.2

Amazing! Still works on 1.21.1.

[NODeeJay]

Yep, but sadly no on 1.21.4 anymore.

[NODeeJay]

Yep, but sadly no on 1.21.4 anymore.