make gcd accept variable arguments

snippets/gcd.md

@@ -1,12 +1,16 @@
 ### gcd
 
-Calculates the greatest common divisor between two numbers.
+Calculates the greatest common divisor between two or more numbers numbers.
 
-Use recursion.
+The helper function uses recursion.
+The helper case takes two arguments x and y
 Base case is when `y` equals `0`. In this case, return `x`.
 Otherwise, return the GCD of `y` and the remainder of the division `x/y`.
 
 ```js
-const gcd = (x, y) => !y ? x : gcd(y, x % y);
+const gcd = (...arr) => {
+    const gcdHelper = (x, y) => !y ? x : gcd(y, x % y);
+    return arr.reduce((a,b) => gcdHelper(a,b))
+}
 // gcd (8, 36) -> 4
 ```