I know there is/was a thread where you post to get this achievement, but I can't find it; my apologies if it still exists and this thread is redundant.
I just made a significant edit to the Game Help:Making your Objects.package file Read-Only page. The file locations are completely different and much less clearly labeled when you have the Ultimate Collection, so I added a list of those file paths, complete with the different Created and Modified dates that show up for me. (I also switched NL and Uni in the list because Uni came first; if I shouldn't have done that, my bad.) I'm not sure if this is enough to deserve the Wikid! achievement, but I think it's enough to be worth asking.