Added go mod, imply one die in absence of count

main.go

@@ -20,6 +20,9 @@ func main() {
 			parm = os.Args[1] + "d" + os.Args[2]
 		}
 	}
+	if strings.HasPrefix(parm, "d") {
+		parm = "1" + parm
+	}
 
 	r = rand.New(rand.NewSource(time.Now().UnixNano()))
 	num, sides, times := parseParm(parm)