Issue Description:

On swift.org in the Package Manager, Example Usage section at URL:

https://swift.org/package-manager/#example-usage

In the second paragraph of subsection 'Using Build Configuration Statements' it says:

"Because the Swift Standard Library does not provide a random number generator, this method must call a function imported from a system module."

The Swift Standard Library has had random APIs since Swift 4.2.

The SPM documentation is now misleading and gives a new Swift user the incorrect impression that they need to manually import and configure lower-level system calls correctly on macOS and Linux to get basic random number functionality.

Suggest updating the documentation to something like.

'Although the Swift Standard Library provides API for random number generation, for demonstration purposes this method will call a function imported from a system module.'

Possibly also adding a note after this section that says:

'Although the shuffleInPlace() method is implemented here for demonstration purposes, the Swift Standard Library provides a shuffle() method to shuffle mutable collections such as Array in place.'