feat/ update readme

Author: nik-rev

15_totalIntegers/README.md

@@ -1,3 +1,7 @@
-# Exercise 13 - totalIntegers
+# Exercise 15 - totalIntegers
 
-Description of the exercise goes here.
+Write a function that when given a multi-dimensional integer array, return the total number of integers stored inside this array
+
+```javascript
+totalIntegers([[[5], 3], 0, 2, ['foo'], [], [4, [5, 6]]]); // returns 7
+```