fix: correct grep patterns in dialogue scripts

Author: jakr-s

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

@@ -5,4 +5,4 @@ set -euo pipefail
 # TODO: Write a command to output every line in dialogue.txt said by the Doctor.
 # The output should contain 6 lines.
 
-grep "^[Doctor:]" dialogue.txt
+grep "^Doctor:" dialogue.txt

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

individual-shell-tools/grep/script-07.sh

@@ -5,4 +5,4 @@ set -euo pipefail
 # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has.
 # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0.
 
-grep -cH "^[Doctor:]" *.txt
+grep -c "^Doctor:" *.txt