generate .ics file for calendar

[yuxineverforever]

Hi @lipiji @sdogsq @oraluben @zwillim @Hsword ,
Good project and good UI design!
Could someone help write some functionality to generate .ics file?

The only two options we have are: 1) google calendar 2) apple calendar
However, there are still a lot of people still using other calendars for various reasons.
They all use the standard calendar format file: .ics

Also, if someone can help add the functionality to let users set multiple conference deadline, and generate a single .ics file for that could be better!

[YinAoXiong]

looking forward to this feature