Migrate .NET 3.1/5 WPF guide from dotnet docs (#48)

* add toc/bread changes

* add xaml-services

* add ported wpf content

* add xaml-services info to docfx

* Fix links 1

* Fix links 2

* Fix links 3

* Fix links 4

* Fix links 5

* Fix links 6

* Fix links 7

* Fix xaml-services link

* Fix snippets 1

* Fix snippets 2

* adjust breadcrumb and toc

* remove preserve-view from breadcrumbs

* add empty view to toc item xaml

* update include

* remove contextual toc for vs article :(

dotnet-desktop-guide/net/wpf/data/snippets/data-binding-overview/vb/FutureDateRule.vb

@@ -0,0 +1,30 @@
+Imports System.Globalization
+
+' <FutureDateRule>
+Public Class FutureDateRule
+    Inherits ValidationRule
+
+    Public Overrides Function Validate(value As Object, cultureInfo As CultureInfo) As ValidationResult
+
+        Dim inputDate As Date
+
+        ' Test if date is valid
+        If Date.TryParse(value.ToString, inputDate) Then
+
+            ' Date is not in the future, fail
+            If Date.Now > inputDate Then
+                Return New ValidationResult(False, "Please enter a date in the future.")
+            End If
+
+        Else
+            ' // Date Is Not a valid date, fail
+            Return New ValidationResult(False, "Value is not a valid date.")
+        End If
+
+        ' Date is valid and in the future, pass
+        Return ValidationResult.ValidResult
+
+    End Function
+
+End Class
+' </FutureDateRule>