feat: add date button theme.

demo/Ursa.Demo/ViewModels/DatePickerDemoViewModel.cs

@@ -0,0 +1,6 @@
+namespace Ursa.Demo.ViewModels;
+
+public class DatePickerDemoViewModel
+{
+    
+}

demo/Ursa.Demo/ViewModels/MainViewViewModel.cs

@@ -31,6 +31,7 @@ public class MainViewViewModel : ViewModelBase
             MenuKeys.MenuKeyBreadcrumb => new BreadcrumbDemoViewModel(),
             MenuKeys.MenuKeyClassInput => new ClassInputDemoViewModel(),
             MenuKeys.MenuKeyClock => new ClockDemoViewModel(),
+            MenuKeys.MenuKeyDatePicker => new DatePickerDemoViewModel(),
             MenuKeys.MenuKeyDialog => new DialogDemoViewModel(),
             MenuKeys.MenuKeyDivider => new DividerDemoViewModel(),
             MenuKeys.MenuKeyDisableContainer => new DisableContainerDemoViewModel(),

demo/Ursa.Demo/ViewModels/MenuViewModel.cs

@@ -18,6 +18,7 @@ public class MenuViewModel: ViewModelBase
             new() { MenuHeader = "Button Group", Key = MenuKeys.MenuKeyButtonGroup },
             new() { MenuHeader = "Class Input", Key = MenuKeys.MenuKeyClassInput },
             new() { MenuHeader = "Clock", Key = MenuKeys.MenuKeyClock, Status = "New" },
+            new() { MenuHeader = "Date Picker", Key = MenuKeys.MenuKeyDatePicker },
             new() { MenuHeader = "Dialog", Key = MenuKeys.MenuKeyDialog },
             new() { MenuHeader = "Disable Container", Key = MenuKeys.MenuKeyDisableContainer },
             new() { MenuHeader = "Divider", Key = MenuKeys.MenuKeyDivider },
@@ -63,6 +64,7 @@ public static class MenuKeys
     public const string MenuKeyBreadcrumb= "Breadcrumb";
     public const string MenuKeyClassInput = "Class Input";
     public const string MenuKeyClock = "Clock";
+    public const string MenuKeyDatePicker = "DatePicker";
     public const string MenuKeyDialog = "Dialog";
     public const string MenuKeyDivider = "Divider";
     public const string MenuKeyDisableContainer = "DisableContainer";