Use maps.Keys

[stefanvanburen]

small/cmd/small/main.go

Lines 47 to 51 in 72cb44f

	supportedTransforms := small.SupportedTransformations()
	supportedTransformNames := make([]string, 0, len(supportedTransforms))
	for supportedTransformName := range supportedTransforms {
	supportedTransformNames = append(supportedTransformNames, supportedTransformName)
	}

This can use maps.Keys - currently not in the standard library, so should wait until it's there.