Add more clarification

Author: dodyg

projects/.net8/RazorComponentOne/README.md

@@ -1,3 +1,5 @@
 # Razor Component SSR
 
-This sample demonstrates how to use Razor Components with Server-Side Rendering (SSR).
+This sample demonstrates how to use Razor Components with Server-Side Rendering (SSR).
+
+`app.MapRazorComponents<RazorComponentOne.Shared.MainLayout>();` map all the razor components in the assembly. There is nothing special about `MainLayout`. Any class from your target assembly will do.