add summary comment.

src/DotNetCore.CAP/CAP.ServiceCollectionExtensions.cs

@@ -32,12 +32,14 @@ namespace Microsoft.Extensions.DependencyInjection
 
             AddSubscribeServices(services);
 
+            // serializer and model binder
             services.TryAddSingleton<IContentSerializer, JsonContentSerializer>();
             services.TryAddSingleton<IConsumerServiceSelector, DefaultConsumerServiceSelector>();
             services.TryAddSingleton<IModelBinderFactory, ModelBinderFactory>();
             services.TryAddSingleton<IConsumerInvokerFactory, ConsumerInvokerFactory>();
             services.TryAddSingleton<MethodMatcherCache>();
 
+            //bootstrap
             services.AddSingleton<IProcessingServer, ConsumerHandler>();
             services.AddSingleton<IProcessingServer, CapProcessingServer>();
             services.AddSingleton<IBootstrapper, DefaultBootstrapper>();

src/DotNetCore.CAP/IProcessingServer.cs

@@ -4,7 +4,7 @@ namespace DotNetCore.CAP
 {
     /// <inheritdoc />
     /// <summary>
-    /// A process thread abstract of job process.
+    /// A process thread abstract of message process.
     /// </summary>
     public interface IProcessingServer : IDisposable
     {