add GeneratorDef

src/content/content_fwd.hpp

@@ -5,7 +5,7 @@
 class Content;
 class ContentPackRuntime;
 
-enum class ContentType { NONE, BLOCK, ITEM, ENTITY };
+enum class ContentType { NONE, BLOCK, ITEM, ENTITY, GENERATOR };
 
 enum class ResourceType : size_t { CAMERA, LAST = CAMERA };