Update README.md

Author: alesanchezr

exercises/03.2-Retrieve-Items/README.md

@@ -4,7 +4,7 @@ tutorial: https://www.youtube.com/watch?v=rWYIgofIAME
 
 # `03.2` Retrieve Items
 
-The only way to access a particular element in an array is by using an index. An index is an integer number, that represents the position you want to access in the array.
+The only way to access a particular element in an array is by using an index. An index is an integer `number` that represents the position you want to access in the array.
 
 You need to wrap the index into brackets like this:
 ```js