Add XML docs to core packages

src/Microsoft.AspNetCore.NodeServices/HostingModels/INodeInstance.cs

@@ -4,8 +4,20 @@ using System.Threading.Tasks;
 
 namespace Microsoft.AspNetCore.NodeServices.HostingModels
 {
+    /// <summary>
+    /// Represents an instance of Node.js to which Remote Procedure Calls (RPC) may be sent.
+    /// </summary>
     public interface INodeInstance : IDisposable
     {
+        /// <summary>
+        /// Asynchronously invokes code in the Node.js instance.
+        /// </summary>
+        /// <typeparam name="T">The JSON-serializable data type that the Node.js code will asynchronously return.</typeparam>
+        /// <param name="cancellationToken">A <see cref="CancellationToken"/> that can be used to cancel the invocation.</param>
+        /// <param name="moduleName">The path to the Node.js module (i.e., JavaScript file) relative to your project root that contains the code to be invoked.</param>
+        /// <param name="exportNameOrNull">If set, specifies the CommonJS export to be invoked. If not set, the module's default CommonJS export itself must be a function to be invoked.</param>
+        /// <param name="args">Any sequence of JSON-serializable arguments to be passed to the Node.js function.</param>
+        /// <returns>A <see cref="Task{TResult}"/> representing the completion of the RPC call.</returns>
         Task<T> InvokeExportAsync<T>(CancellationToken cancellationToken, string moduleName, string exportNameOrNull, params object[] args);
     }
 }