Update dependency-properties.md (#6115)

Author: yauhenipakala

docs/standard/design-guidelines/dependency-properties.md

@@ -37,7 +37,7 @@ A dependency property (DP) is a regular property that stores its value in a prop
 
  A classic example of an attached property is the <xref:System.Windows.Controls.Grid.Column%2A?displayProperty=nameWithType> property. The property represents Button’s (not Grid’s) column position, but it is only relevant if the Button is contained in a Grid, and so it's "attached" to Buttons by Grids.  
 
-```  
+```xaml
 <Grid>  
     <Grid.ColumnDefinitions>  
         <ColumnDefinition />  
@@ -51,7 +51,7 @@ A dependency property (DP) is a regular property that stores its value in a prop
 
  The definition of an attached property looks mostly like that of a regular dependency property, except that the accessors are represented by static Get and Set methods:  
 
-```  
+```csharp
 public class Grid {  
 
     public static int GetColumn(DependencyObject obj) {