Add ReSharper directive to FileExtension.cs

Disabled the InconsistentNaming warning for the FileExtension constants to prevent ReSharper from flagging naming conventions.

Author: lzcapp

KindleMate2.Shared/Constants/FileExtension.cs

@@ -1,4 +1,5 @@
-namespace KindleMate2.Shared.Constants {
+// ReSharper disable InconsistentNaming
+namespace KindleMate2.Shared.Constants {
     public static class FileExtension {
         public const string PNG = ".png";
         public const string DAT = ".dat";