The .NET Core Configuration Provider Has Been Updated

As part of the [App Configuration GA plan](https://github.com/Azure/AppConfiguration-Announcements/issues/2), we’re releasing a new version ([3.0.0-preview-010550001-251](https://www.nuget.org/packages/Microsoft.Extensions.Configuration.AzureAppConfiguration)) of the .NET Core configuration provider. This new release includes the following changes:

- Added support for authentication using Azure Active Directory.
- Reworked Azure Managed Identity support to align with other Azure SDKs.
- Removed dependencies that have been deprecated.
- Refactored a number of APIs based on user feedback.

Please check out the [release notes](https://aka.ms/MicrosoftExtensionsConfigurationAzureAppConfigurationReleaseNotes) for more information and guidance on how to migrate to the newest version. We believe that this version will be very close to the final GA build. We encourage you to switch to it soon. As always, [let us know](https://github.com/Azure/AppConfiguration/issues/new) if you encounter any issues.