Fix error in TwigComponent documentation breaking the display of the default config

Author: maelanleborgne

src/TwigComponent/doc/index.rst

@@ -62,15 +62,14 @@ That's it! We're ready to go! If you're not using Symfony Flex, add a config
 file to control the template directory for your components:
 
 .. _default_config:
+.. code-block:: yaml
 
-```
-# config/packages/twig_component.yaml
-twig_component:
-    anonymous_template_directory: 'components/'
-    defaults:
-        # Namespace & directory for components
-        App\Twig\Components: 'components/'
-```
+    # config/packages/twig_component.yaml
+    twig_component:
+        anonymous_template_directory: 'components/'
+        defaults:
+            # Namespace & directory for components
+            App\Twig\Components: 'components/'
 
 Component Basics
 ----------------