Fix typo in doccomment in ContainerResourceBuilderExtensions.cs (#9342)

* fix doccomment

* use escaped characters

Author: KuraiAndras

src/Aspire.Hosting/ContainerResourceBuilderExtensions.cs

@@ -789,8 +789,8 @@ public static IResourceBuilder<T> WithContainerFiles<T>(this IResourceBuilder<T>
     /// builder.AddContainer("mycontainer", "myimage")
     ///     .WithContainerFiles("/", (context, cancellationToken) =>
     ///     {
-    ///         var appModel = context.ServiceProvider.GetRequiredService{DistributedApplicationModel}();
-    ///         var postgresInstances = appModel.Resources.OfType{PostgresDatabaseResource}();
+    ///         var appModel = context.ServiceProvider.GetRequiredService&lt;DistributedApplicationModel&gt;();
+    ///         var postgresInstances = appModel.Resources.OfType&lt;PostgresDatabaseResource&gt;();
     ///
     ///         return [
     ///             new ContainerDirectory