hotfix: data folder fix

SfeduSchedule/AppConsts.cs

@@ -26,5 +26,5 @@ public static class AppConsts
     // File paths
     public const string JwtFileName = "jwt.txt";
     public const string EmployeesFileName = "employees.json";
-    public const string DataFolderName = "Data";
+    public const string DataFolderName = "data";
 }