Page 31 Mentions "Sources" Directory but No Sources Folder in Download

Page 31 mentions a “Sources” directory, but there isn’t one in the downloaded folder. Why is this mentioned like this rather than saying open a new file in a new folder? Is there some content that is available in “Sources” that is needed for the linked list project or is this a copy error?

In each one of the playgrounds, if you open the file navigator there is a directory embedded in the playground called Sources. Every playground has a sources directory that you can put compiled code into.