Update article.md

Simplify wording

Author: gleachkr

1-js/05-data-types/07-map-set/article.md

@@ -291,7 +291,7 @@ set.forEach((value, valueAgain, set) => {
 
 Note the funny thing. The callback function passed in `forEach` has 3 arguments: a `value`, then *the same value* `valueAgain`, and then the target object. Indeed, the same value appears in the arguments twice.
 
-That's for compatibility with `Map` where the callback passed `forEach` has three arguments. Looks a bit strange, for sure. But this convention may help to replace `Map` with `Set` in certain cases with ease, and vice versa.
+That's for compatibility with `Map` where the callback passed `forEach` has three arguments. Looks a bit strange, for sure. But this may help to replace `Map` with `Set` in certain cases with ease, and vice versa.
 
 The same methods `Map` has for iterators are also supported: