docs: add xml comments for Essentials routing

src/PepperDash.Essentials.Core/Routing/IRoutingWithFeedback.cs

@@ -3,14 +3,25 @@ using System;
 
 namespace PepperDash.Essentials.Core
 {
+    /// <summary>
+    /// Delegate for handling route change events on devices implementing <see cref="IRoutingWithFeedback"/>.
+    /// </summary>
+    /// <param name="midpoint">The routing device where the change occurred.</param>
+    /// <param name="newRoute">A descriptor of the new route that was established.</param>
     public delegate void RouteChangedEventHandler(IRoutingWithFeedback midpoint, RouteSwitchDescriptor newRoute);
     /// <summary>
-    /// Defines an IRouting with a feedback event
+    /// Defines a routing device (<see cref="IRouting"/>) that provides feedback about its current routes.
     /// </summary>
     public interface IRoutingWithFeedback : IRouting
     {
+        /// <summary>
+        /// Gets a list describing the currently active routes on this device.
+        /// </summary>
         List<RouteSwitchDescriptor> CurrentRoutes { get; }
 
+        /// <summary>
+        /// Event triggered when a route changes on this device.
+        /// </summary>
         event RouteChangedEventHandler RouteChanged;
     }
 }