[Console] add documentation for kernel-aware console applications

components/console/single_command_tool.rst

@@ -54,3 +54,34 @@ Of course, you can still register a command as usual::
 
   $application->setDefaultCommand($command->getName(), true);
   $application->run();
+
+If you need to create a kernel-aware application, you can use
+``Symfony\Bundle\FrameworkBundle\Console\Application`` instead of ``Symfony\Component\Console\Application``::
+
+  #!/usr/bin/env php
+  <?php
+  require __DIR__.'/vendor/autoload.php';
+
+  use Symfony\Bundle\FrameworkBundle\Console\Application;
+  use Symfony\Component\Console\Input\InputArgument;
+  use Symfony\Component\Console\Input\InputInterface;
+  use Symfony\Component\Console\Input\InputOption;
+  use Symfony\Component\Console\Output\OutputInterface;
+
+  use Acme\Command\DefaultCommand;
+
+  $kernel = new AppKernel('dev', true);
+  $application = new Application($kernel);
+  $command = new DefaultCommand();
+
+  $application->add($command);
+
+  $application->setDefaultCommand($command->getName(), true);
+  $application->run();
+
+.. note::
+  An instance of ``Symfony\Bundle\FrameworkBundle\Console\Application`` will automatically
+  load all default commands. If you want to change this behaviour, you can pass ``false``
+  as the second argument when creating the object::
+
+    $application = new Application($kernel, false);