Add module export code for webpack

[dewwwald]

Use this code to return modules for webpack. See my PR:

https://github.com/onozaty/suggest.js/pull/7

if(typeof define === 'function' && define.amd) {
    define('Suggest', function () {
      return Suggest;
    });
  } else if (typeof module !== 'undefined' && module.exports) {
    module.exports = Suggest;
  } else {
    window.Suggest = Suggest;
  }