unity AddObjectToAsset
https://forum.unity.com/threads/is-it-possible-to-add-a-prefab-as-a-sub-asset-to-a-scriptable-object.666007/
t is possible to add a ScriptableObject as a sub-asset to a prefab
https://forum.unity.com/threads/is-it-possible-to-add-a-prefab-as-a-sub-asset-to-a-scriptable-object.666007/
t is possible to add a ScriptableObject as a sub-asset to a prefab