Added resource table plugin

example/Random Upgrades/upgrade_data_weapon.gd

@@ -0,0 +1,16 @@
+@tool
+extends "res://example/Random Upgrades/upgrade_data.gd"
+
+@export var weapon_damage := 0.0
+@export var weapon_cooldown := 0.0
+@export var weapon_dps := 0.0:
+    set(v):
+        weapon_damage = v * weapon_cooldown
+    get:
+        return weapon_damage / weapon_cooldown if weapon_cooldown != 0.0 else 0.0
+
+
+func _validate_property(property: Dictionary) -> void:
+    if property.name == &"weapon_dps":
+        # Show in inspector, but don't save into resource file.
+        property.usage = PROPERTY_USAGE_EDITOR