created basic building class

started building groups
temp ui placed
#11 #13 #6

scripts/building.gd

@@ -0,0 +1,8 @@
+class_name Building
+extends Resource
+
+@export var corruption_pattern: ExpansionBase
+@export var atlas_texture_region: Vector2i
+@export var name: String
+@export var description: String
+@export var cost: Dictionary