Added ExportToYaml method to IExportService interface

Author: DavidSuescunPelegay

src/jQueryDatatableServerSideNetCore/Services/ExportService/IExportService.cs

@@ -16,5 +16,7 @@ public interface IExportService
         byte[] ExportToJson(List<TestRegister> registers);
 
         byte[] ExportToXml(List<TestRegister> registers);
+
+        byte[] ExportToYaml(List<TestRegister> registers);
     }
 }