factorial formula adjustement

The formula in book is incorrect because it doesn't include the factorial(0) case and leads to infinite recursion in this case.

03_recursion/javascript/03_factorial.js

@@ -4,7 +4,7 @@
  * @returns {number} Result
  */
 function fact(x) {
-  if (x === 1) return 1;
+  if (x === 0) return 1;
   return x * fact(x - 1);
 }