Add basic documentation

Author: joel-jeremy

README.md

@@ -1,2 +1,11 @@
 # Xer.Cqrs.Extensions.Autofac
-Autofac implementation for Xer.Cqrs
+Extension for Autofac's `ContainerBuilder` to allow easy registration of command handlers and event handlers.
+
+```csharp
+public void ConfigureServices(Autofac.ContainerBuilder container)
+{
+    // Register all CQRS components.
+    container.RegisterCqrs(typeof(CommandHandler).Assembly, 
+                           typeof(EventHandler).Assembly);
+}
+```