shuffle icon link batches before putting them in the channel

pipeline/03_icon_download/main.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"math/rand"
 	"os"
 	"sync"
 	"sync/atomic"
@@ -137,6 +138,9 @@ func main() {
 				break
 			}
 
+			rand.Shuffle(len(icons), func(i, j int) {
+				icons[i], icons[j] = icons[j], icons[i]
+			})
 			for _, icon := range icons {
 				iconCh <- icon
 			}