Update README.md

subjects/where-do-we-go/README.md

@@ -19,7 +19,7 @@ Write the function `explore` which creates a page displaying the list of `places
 ### Notions
 
 - [Scroll event](https://developer.mozilla.org/en-US/docs/Web/API/Element/scroll_event)
-- [`window`](https://developer.mozilla.org/en-US/docs/Web/API/Window): [`innerHeight`](https://developer.mozilla.org/en-US/docs/Web/API/Window/innerHeight), [`scrollY`](https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollY)
+- [`window`](https://developer.mozilla.org/en-US/docs/Web/API/Window): [`innerHeight`](https://developer.mozilla.org/en-US/docs/Web/API/Window/innerHeight), [`scrollY`](https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollY), [`pageYOffset`](https://developer.mozilla.org/en-US/docs/Web/API/Window/pageYOffset)
 - Take a look at the [DMS coordinates system](https://en.wikipedia.org/wiki/Decimal_degrees)
 
 ### Provided files