Fix script-06.sh solution.

Author: anosidium

individual-shell-tools/grep/script-06.sh

@@ -5,4 +5,4 @@ set -euo pipefail
 # TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor.
 # The output should contain two filenames.
 
-grep -l 'Doctor' *.txt
+grep -l '^Doctor:' *.txt