docs: fixed source link (#214)

Author: COil

README.md

@@ -151,7 +151,7 @@ Have a look at the specific [documentation](https://github.com/strangebuzz/Micro
   * [Configuration](https://github.com/strangebuzz/MicroSymfony/blob/main/.php-cs-fixer.dist.php)
 * Tests ([demo](https://www.strangebuzz.com/en/blog/introducing-the-microsymfony-application-template#h2_7))
   * Unit test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/Unit/Helper/StringHelperTest.php) 
-  * Integration test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/Integration/Twig/Extension/MarkdownExtensionTest.php) 
+  * Integration test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/Integration/Twig/Extension/RoutingExtensionTest.php) 
   * Functional test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/Functional/Controller/ComposerActionTest.php) 
   * API test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/Api/Controller/SlugifyActionTest.php) 
   * E2E test [example](https://github.com/strangebuzz/MicroSymfony/blob/main/tests/E2E/Controller/AppControllerTest.php)