fix append_or_replace

tools/append_or_replace

@@ -11,7 +11,7 @@ STRING=$2
 FILE=$3
 
 if ! grep -Eq "$REGEX" "$FILE"; then
-	printf "%s\n" "$STRING" >>"$FILE"
+	builtin echo -e "$STRING" >>"$FILE"
 	echo 'appended'
 else
 	sed -Ei "s|$REGEX|$STRING|g" "$FILE"