iCloud support

[jedahan]

If you are using iCloud, heres how to configure it:

url: https://caldav.icloud.com/
user: <your-apple-id-here>
password: <app-specific-password>

How to make an app-specific-password?

From https://support.apple.com/en-us/102654

1. Sign in to appleid.apple.com.
2. In the Sign-In and Security section, select App-Specific Passwords.
3. Select Generate an app-specific password or select the Add button (Blue plus sign icon.), then follow the steps on your screen.

[tenJirka]

This is quite a surprise to me, I'm not an Apple user so enabling iCloud linking wasn't intended, but I'm glad it works.
I'll add this example to the Readme as well with a link to this discussion.

Thank you @jedahan !