Update manage-app-host.mdx

src/frontend/src/content/docs/testing/manage-app-host.mdx

@@ -21,7 +21,7 @@ When writing functional or integration tests with Aspire, managing the [AppHost]
 
 For writing tests with Aspire, you use the [Aspire.Hosting.Testing](https://www.nuget.org/packages/Aspire.Hosting.Testing) NuGet package which contains some helper classes to manage the AppHost instance in your tests.
 
-## Use the `DistributedApplicationTestingBuilder` class
+### Use the `DistributedApplicationTestingBuilder` class
 
 In the [tutorial on writing your first test](/testing/write-your-first-test/), you were introduced to the `DistributedApplicationTestingBuilder` class which can be used to create the AppHost instance:
 
@@ -124,7 +124,7 @@ public class WebTests
 
 By capturing the AppHost in a field when the test run is started, you can access it in each test without the need to recreate it, decreasing the time it takes to run the tests. Then, when the test run completes, the AppHost is disposed, which cleans up any resources that were created during the test run, such as containers.
 
-## Pass arguments to your AppHost
+### Pass arguments to your AppHost
 
 You can access the arguments from your AppHost with the `args` parameter. Arguments are also passed to [.NET's configuration system](https://learn.microsoft.com/dotnet/core/extensions/configuration), so you can override many configuration settings this way. In the following example, you override the [environment](https://learn.microsoft.com/aspnet/core/fundamentals/environments) by specifying it as a command line option:
 
@@ -167,7 +167,7 @@ public async Task DisableVolumesFromTest()
 }
 ```
 
-## Use the `DistributedApplicationFactory` class
+### Use the `DistributedApplicationFactory` class
 
 While the `DistributedApplicationTestingBuilder` class is useful for many scenarios, there might be situations where you want more control over starting the AppHost, such as executing code before the builder is created or after the AppHost is built. In these cases, you implement your own version of the `DistributedApplicationFactory` class. This is what the `DistributedApplicationTestingBuilder` uses internally.