Add docs to RouteValuesAddress (#695)

src/Microsoft.AspNetCore.Routing/RouteValuesAddress.cs

@@ -3,12 +3,24 @@
 
 namespace Microsoft.AspNetCore.Routing
 {
+    /// <summary>
+    /// An address of route name and values.
+    /// </summary>
     public class RouteValuesAddress
     {
+        /// <summary>
+        /// Gets or sets the route name.
+        /// </summary>
         public string RouteName { get; set; }
 
+        /// <summary>
+        /// Gets or sets the route values that are explicitly specified.
+        /// </summary>
         public RouteValueDictionary ExplicitValues { get; set; }
 
+        /// <summary>
+        /// Gets or sets ambient route values from the current HTTP request.
+        /// </summary>
         public RouteValueDictionary AmbientValues { get; set; }
     }
 }