Update links to documentation

Author: shahariaazam

README.md

@@ -8,7 +8,7 @@ them.
 Resources
 ---------
 
-  * [Documentation](https://symfony.com/doc/current/components/event_dispatcher/index.html)
+  * [Documentation](https://symfony.com/doc/current/components/event_dispatcher.html)
   * [Contributing](https://symfony.com/doc/current/contributing/index.html)
   * [Report issues](https://github.com/symfony/symfony/issues) and
     [send Pull Requests](https://github.com/symfony/symfony/pulls)