Fix expected output in sed exercise instructions (#353)

Fix expected output: change 'with' to 'wIth' in sed exercise
instructions

Author: Abubakar-Meigag

individual-shell-tools/sed/script-01.sh

@@ -4,4 +4,4 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
 # The output should contain 11 lines.
-# The first line of the output should be: "ThIs Is a sample fIle for experImentIng with sed.".
+# The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".