chore: Keep WithCleanUp(true) its implicitly set

Author: HofmeisterAn

src/Testcontainers/Builders/ContainerBuilder.cs

@@ -11,14 +11,15 @@ namespace DotNet.Testcontainers.Builders
   /// A fluent Docker container builder.
   /// </summary>
   /// <remarks>
-  /// The container builder configuration requires image tag to be provided. Either invoke the constructor with image tag as a parameter (recommended) or call the <see cref="ContainerBuilder{TBuilderEntity, TContainerEntity, TConfigurationEntity}.WithImage(string)" /> method after creating instance of <see cref="ContainerBuilder" />.
+  /// The container builder requires a container image, which must be provided through the constructor.
   /// </remarks>
   /// <example>
   ///   The default configuration is equivalent to:
   ///   <code>
   ///   _ = new ContainerBuilder()
   ///     .WithDockerEndpoint(TestcontainersSettings.OS.DockerEndpointAuthConfig)
   ///     .WithLabel(DefaultLabels.Instance)
+  ///     .WithCleanUp(true)
   ///     .WithLogger(ConsoleLogger.Instance)
   ///     .WithImagePullPolicy(PullPolicy.Missing)
   ///     .WithPortForwarding()