Allow renaming holiday names

[no0ID]

In some languages the holiday names are too long and messing up the calendar if other events are scheduled to the same day

[no0ID]

C'mon, the Slovak holidays names are horrible and way toooooo long...

[jurajmajer]

You probably mean holiday names on website e.g. https://holidays.kayaposoft.com/public_holidays.php?country=svk&year=2021&region=bl. Holiday names there should be editable before importing to calendar, right? This is a GitHub project for the library (service) which provides public holidays. holidays.kayaposoft.com just uses this library. So yes, it is a good idea to implement it in holidays.kayaposoft.com but not here in the library. Btw Slovak holiday names are taken exactly as they appear in the law.

I have done holidays.kayaposoft.com so I will write this feature to the TODO list. 👍