Added SwitchPresenter in description of Control.Primitives project

Microsoft.Toolkit.Uwp.UI.Controls.Primitives/Microsoft.Toolkit.Uwp.UI.Controls.Primitives.csproj

@@ -10,6 +10,7 @@
 			- AdaptiveGridView: Presents items in an evenly-spaced set of columns to fill the total available space.
 			- DockPanel: Define areas where you can arrange child elements either horizontally or vertically, relative to each other.
 			- StaggeredPanel: Layout of items in a column approach where an item will be added to whichever column has used the least amount of space.
+			- SwitchPresenter: A presenter which can act as a switch statement for layout providing alternate layouts based on a value.
 			- UniformGrid: Presents items in an evenly-spaced set of rows or columns to fill the total available display space.
 			- WrapPanel: Positions child elements in sequential position from left to right and breaks content to the next line.
 		</Description>