Update README.md

Author: josemoracard

exercises/39-class-that-iterates/README.md

@@ -2,8 +2,8 @@
 
 ## 📝 Instructions:
 
-1. Define a class with a generator that can iterate the numbers that are divisible by 7, between a given range `0` and `n`.
+1. Define a class with a generator function that can iterate the numbers that are divisible by 7, between a given range `0` and `n`.
 
 ## 💡 Hint:
 
-+ Consider using `yield`.
++ Read about generator functions and `yield`: https://sentry.io/answers/python-yield-keyword/