add EFCore.SoftDelete (#2500)

* add EFCore.SoftDelete

An implementation for soft deleting entities for EntityFramework Core.

* add efcore.softdelere extension

an implementation for soft deletes in efcore 3.1 nad later

* Add EFCore.SoftDelete

An implementation for soft deleting entities for EntityFramework Core.

* Ass EFCore.SoftDelete

An implementation for soft deleting entities for EntityFramework Core.

* Add EFCore.SoftDelete extension

An implementation for soft deleting entities for EntityFramework Core.

* Add EFCore.SoftDelete

An implementation for soft deleting entities. For EF Core 3.

* Add EFCore.SoftDelete extension

An implementation for soft deleting entities. For EF Core 3.

Author: AshkanAbd

entity-framework/core/extensions/index.md

@@ -225,3 +225,9 @@ Alternative translator of LINQ queries to SQL expressions. For EF Core: 3.
 Includes support for advanced SQL features such as CTEs, bulk copy, table hints, windowed functions, temporary tables, and database-side create/update/delete operations.
 
 [GitHub repository](https://github.com/linq2db/linq2db.EntityFrameworkCore)
+
+### EFCore.SoftDelete
+
+An implementation for soft deleting entities. For EF Core: 3.
+
+[NuGet](https://www.nuget.org/packages/EFCore.SoftDelete)