Update README.md

/**
 * Pick item.
 * It exists some results: NOT_IN_RANGE, VANISH, BAG_FULL, SUCCESS
 *
 * @param {Number} entityId
 * @return {Object}
 * @api public
 */
Player.prototype.pickItem = function(entityId) {
  var item = this.area.getEntity(entityId);

  var result = {player : this, item : item};

  if(!item) {
    result.result = consts.Pick.VANISH;
    this.emit('pickItem', result);
    return result;
  }

  // TODO: remove magic pick distance 200
  if(!formula.inRange(this, item, 200)) {
    result.distance = 200;
    result.result = consts.Pick.NOT_IN_RANGE;
    return result;
  }

  var index = this.bag.addItem({id: item.kindId, type: item.type});
  if (index < 1) {
    result.result = consts.Pick.BAG_FULL;
    this.emit('pickItem', result);
    return result;
  }

  result.index = index;
  result.result = consts.Pick.SUCCESS;
  this.emit('pickItem', result);
  return result;
};