chore(curriculum): change to US spelling Fulfill (freeCodeCamp#60927)

Author: clarencepenz

curriculum/challenges/english/25-front-end-development/lab-mood-board/673b3d6b7ef7318eef926d5a.md

@@ -12,7 +12,7 @@ A mood board is a collage of images and text that conveys a general idea, goal,
 
 In this lab, you will create a mood board using reusable React components. The CSS has already been provided for you.
 
-Fulfil the user stories below and get all the tests to pass to complete the lab.
+Fulfill the user stories below and get all the tests to pass to complete the lab.
 
 **User Stories:**