chore: add terrain surface config

src/types/world/terrainSurface.ts

@@ -0,0 +1,18 @@
+export type TerrainSurfaceKind =
+  | "grass"
+  | "path"
+  | "water"
+  | "garden"
+  | "dirt"
+  | "rock";
+
+export type TerrainSurfaceRgb = readonly [number, number, number];
+
+export interface TerrainSurfaceColorConfig {
+  hex: string;
+  rgb: TerrainSurfaceRgb;
+  kind: TerrainSurfaceKind;
+  grassTipColor?: string;
+  modelPath?: string;
+  tileSize?: number;
+}