v0.7

Changes:
- Added biomes with 6 types: Plains, Forest, Medium Mountain, High Mountain, Desert, and Ice Plain. Biomes are determined using Perlin noise (temperature and humidity).
- Added tree spawning in Forest biomes.
- Added flowers (poppies and dandelions) in Plains and Forest biomes.
- You can now connect to a server (multiplayer gameplay not functional yet).
- Added textures for items and blocks using an atlas system.
- Refactored the meshing system to support complex shapes (e.g., stairs and slabs).
- Added vertex coloring for grass blocks.

Full Changelog: v0.6...v0.7