InvoiceManagementApp
https://alexcodetuts.com/2020/02/05/asp-net-core-3-1-clean-architecture-invoice-management-app-part-1/
https://alexcodetuts.com/2020/02/06/asp-net-core-3-1-clean-architecture-invoice-management-app-part-2-ef-core-audit/
https://alexcodetuts.com/2020/02/09/asp-net-core-3-1-clean-architecture-invoice-management-app-part-3-mediatr-and-fluentvalidation/