See: https://www.builder.io/blog/utility-types#:~:text=But%2C%20now%20that%20we%20are%20aware%20of%20Readonly%2C%20we%20can%20combine%20that%20with%20its%20sibling%20ArrayReadonly%2C%20and%20a%20little%20bit%20of%20magic%2C%20and%20make%20our%20own%20DeepReadonly%20type%20like%20so%3A
