Clarify idea for improvement 1.

When I was working through this, I found it not completely clear what was meant by 'instead of "6"'. I assumed the document refers to the move numbers in the move list, so that's what this change clarifies.

content/tutorial/tutorial.md

@@ -1090,7 +1090,7 @@ Check out the final result here: [Final Result](https://codepen.io/gaearon/pen/g
 
 If you have extra time or want to practice your new skills, here are some ideas for improvements you could make, listed in order of increasing difficulty:
 
-1. Display the move locations in the format "(1, 3)" instead of "6".
+1. Display the move locations in the format "(1, 3)" in the move list.
 2. Bold the currently selected item in the move list.
 3. Rewrite Board to use two loops to make the squares instead of hardcoding them.
 4. Add a toggle button that lets you sort the moves in either ascending or descending order.