MC-8187 / 2x2 Surrounded Saplings Fix

# [MC-8187] / 2x2 Surrounded Saplings Fix The 2x2 Surrounding Saplings fix for [MC-8187] allows 2x2 saplings such as spruce, jungle and dark oak to grow even when completely surrounded on all 4 sides. ## How does it work? Simple, it fixes an offset in TreeFeature.getTopPosition that makes 2x2 trees check a 3x3 area at the trunk, catching additional blocks that don't determine how the tree should grow. ## How do I use it? Simply install [Fabric] or [Quilt] for Minecraft 1.16 and newer, then install this mod. ## Any side effects? Theoretically, 2x2 trees *may* spawn more frequently in a given world, and old builds not expecting 2x2 saplings to grow may suddenly get a surprise. Any modded trees that are 3x3 may also erroneously check for a 2x2 trunk if it relies on the generator to filter out whether a space is valid. ## Fun facts: - This mod was written on 1.16.5 and works as is on 1.16 through 1.20.1. - I wrote this mod using [Segoe Script](https://learn.microsoft.com/en-us/typography/font-list/segoe-script). - Some hate the compatibility cockroach that is this mod. [Fabric]: https://fabricmc.net/use [Quilt]: https://quiltmc.org/install [MC-8187]: https://bugs.mojang.com/browse/MC-8187