Fix syntax error in recursion.md

There is a syntax error in the last code section in recursion.md.

Original:
````sh
> var operations = (function () {})(
      var even = function (num) { return (num === 0) || odd( num - 1) };
      var odd  = function (num) { return (num  >  0) && even(num - 1) };
      return {
        even: even,
        odd:  odd
      }
    ),
    even = operations.even,
    odd = operations.odd;
> SyntaxError: Unexpected token var
````

After:
````sh
> var operations = (function () {
...       var even = function (num) { return (num === 0) || odd( num - 1) };
...       var odd  = function (num) { return (num  >  0) && even(num - 1) };
...       return {
.....         even: even,
.....         odd:  odd
.....       }
...     })(),
...     even = operations.even,
...     odd = operations.odd;
undefined
> odd = 'unusual';
'unusual'
> even(0)
true
> even(1)
false
> even(42)
true
````