Issue Description:

https://swift.org/package-manager/

Under "Using Build Configuration Statements"

> The implementation of shuffleInPlace() uses the Fisher-Yates algorithm to randomly permute the elements in a collection. Because the Swift Standard Library does not provide a random number generator, this method must call a function imported from a system module. For this function to be compatible with both macOS and Linux, the code uses build configuration statements.

We can probably leave the example package as-is, but it might be confusing for new users to read the above statement. They might think there is some good reason not to use the RNG and collection-shuffling which does now exist in the standard library.

Perhaps something like "pretend the standard library did not provide a random number generator"?