Improvements and Bug fixes.
Improvements:
When creating a reminder column with a frequency of once, you can configure the reminder before expiration function.
Bug fixes:
Fix the problem that the reminder column icon can't appear when the column header is edited with text bold, tilt and other styles in the page table.
改进功能：
创建频率为一次的提醒列时，可配置提前提醒功能。
缺陷修复：
修复页面表格中当列头进行文本加粗、倾斜等样式编辑后，提醒列图标无法出现的问题。