FileWork examples were added

DataAccess/FileDialogs/IFileRepository.cs

@@ -0,0 +1,14 @@
+using System.IO;
+using System.Threading.Tasks;
+
+namespace DataAccess.FileDialogs
+{
+    public interface IFileRepository
+    {
+        Task SaveFileAsync(Stream fileStream, string fileName);
+        Task<Stream> GetFileAsync(string fileName);
+        Task DeleteFileAsync(string fileName);
+        Task UpdateFileAsync(Stream fileStream, string fileName);
+    }
+
+}