refactor: sed script-05

Author: XiaoQuark

individual-shell-tools/sed/script-05.sh

@@ -6,4 +6,4 @@ set -euo pipefail
 # If a line starts with a number and a space, make the line instead end with a space and the number.
 # So line 6 which currently reads "37 Alisha" should instead read "Alisha 37".
 # The output should contain 11 lines.
-sed "s/^\([0-9]\+\) \(.*\)$/\2 \1/" input.txt
+sed -E "s/^([0-9]+) (.*)$/\2 \1/" input.txt