Add a simple function digit_names().

It returns a string representing the name of the single
digit that was passed to it.

Author: danielmiladinov

digit_name.js

@@ -0,0 +1,9 @@
+var digit_name = function () {
+    var names = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];
+
+    return function (n) {
+        return names[n];
+    }
+}();
+
+alert(digit_name(3)); // 'three'