update snippets 1-15

snippets/arrayGcd.md

@@ -7,8 +7,11 @@ Use `Array.reduce()` and the `gcd` formula (uses recursion) to calculate the gre
 ```js
 const arrayGcd = arr => {
   const gcd = (x, y) => !y ? x : gcd(y, x % y);
-  return arr.reduce((a, b) => gcd(a, b));
-};
-// arrayGcd([1,2,3,4,5]) -> 1
-// arrayGcd([4,8,12]) -> 4
+  return arr.reduce((a,b) => gcd(a,b));
+}
+```
+
+```js
+arrayGcd([1,2,3,4,5]) -> 1
+arrayGcd([4,8,12]) -> 4
 ```