fixed ls script-02.sh

Author: TzeMingHo

individual-shell-tools/ls/script-02.sh

@@ -4,5 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command which lists all of the files in the directory named child-directory.
 
-ls -R ./child-directory
+ls ./child-directory
 # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt.