Update upgradeable tutorial to include ownable?


I have recently gone through the /learn/ tutorials and it was really quite clear but I would like to suggest that the upgradeable step build upon the Ownable step.

I don't think there is a good (or obvious) resource for using upgradeable with ownable (or access-control) which I can only assume is a frequent and obvious use-case. By adding it to the tutorial, you would create this resource and remain consistent with previous steps which build upon the Box example.

Thanks for your hard work!