add file list to readme

Author: DevExpressExampleBot

Readme.md

@@ -1,3 +1,10 @@
+<!-- default file list -->
+*Files to look at*:
+
+* [Employees.cs](./CS/DXGrid_AttributesBasedValidation/Employees.cs) (VB: [Employees.vb](./VB/DXGrid_AttributesBasedValidation/Employees.vb))
+* [MainWindow.xaml](./CS/DXGrid_AttributesBasedValidation/MainWindow.xaml) (VB: [MainWindow.xaml](./VB/DXGrid_AttributesBasedValidation/MainWindow.xaml))
+* [MainWindow.xaml.cs](./CS/DXGrid_AttributesBasedValidation/MainWindow.xaml.cs) (VB: [MainWindow.xaml](./VB/DXGrid_AttributesBasedValidation/MainWindow.xaml))
+<!-- default file list end -->
 # How to Implement Attributes-Based Validation