Support sorting array items

[gkampitakis]

First of all thanks a lot for the amazing work on this library.

I was wondering how easy/feasible would be to support not only sorting keys but also sorting items inside an array.

[dolmen]

@gkampitakis Here is a generic utility function that you can use:

func sortedArray[T constraints.Ordered, ST ~[]T](orig ST) ST {
	sorted := make(ST, len(orig))
	copy(sorted, orig)
	sort.SliceStable(sorted, func(i, j int) bool { return sorted[i] < sorted[j] })
	return sorted
}

Full example on the Go Playground.