Update flex/03-flex-header-2/README.md

Co-authored-by: Eric Olkowski <[email protected]>

Author: Torelli

flex/03-flex-header-2/README.md

@@ -4,7 +4,7 @@ We're starting to sneak in a little more CSS that you haven't seen yet. Don't wo
 
 For this one you will probably need to edit the HTML a little bit. Often with flexbox you need to add containers around things to make them go where you need them to go. In this case, you probably want to separate the items that go on the left and right of the header.
 
-Just like you did in the previous exercise with the `ul`, you'll be nesting flex containers inside each other.
+Just like you did in the `02-flex-header` exercise, you'll be nesting flex containers inside each other.
 
 ## Desired outcome
 As with the last example, this one needs to be flexible in the middle, with items pushed to the left and right.