v1.0.0: Introducing CalendarStore API for .NET MAUI!

Here is the first version of the CalendarStore API for .NET MAUI. This library allows you to read and write calendars, events and attendee information from the device for iOS, Android, macOS and Windows!

I noticed this PR on the Xamarin.Essentials repository that unfortunately never got merged. It's a shame that that code will go to waste, so I decided to adapt it to .NET MAUI and wrap it into a nice plugin for you to use!

There are a couple of people involved in trying to bring this functionality to Xamarin.Essentials. Thank you @mattleibow, @nickrandolph, @ScottBTR and @mkieres for the initial work here 👏

To get you started, check out this video on how to read calendar information on my YouTube channel. Or have a look at the README information at the root of this repository.

Please let me know if you find any issues, or even better: help me out with a pull request.