Add expire time

1.Correct the problem that when item sell Quantity exceeds 1000+, the total price will be the same as the unit price and the total price is incorrect.
2.Corrected the problem that the input of unit price and total price can sometimes only enter 7 digits.

1.修复商品数量超过1000+时，总价会与单价相同，总价不正确的问题。
2.修复单价和总价的输入有时只能输入7位数的问题。

Update to the latest version of the game (the time of expiration of goods is not added)
1. You can directly select Average price to sell.
2. Enter Per Unit and Lower Averag for comparison, if Per Unit is more than 20% less than Lower Averag price shows the red exclamation mark and the specific less how many original crystals, do not have to worry about the price is written wrong.
3. Add the tutorial of cfg.

更新到游戏最新版本（商品过期的时间没加）
1.可直接选择平均价格出售。
2.输入的单价与最低平均价格比较，如果单价比最低平均价格少20%以上显示红叹号和具体少了多少原晶，不用再担心价格写错了。
3.添加cfg的教程。

Add a button to quickly create a new list of items at the last entered price, without having to enter the same price again.

添加一个按钮，可以以最后的一次价格快速创建一个新的商品，不用再次输入相同价格。