Fixed RST directives

Author: javiereguiluz

routing.rst

@@ -301,7 +301,7 @@ concise, but it can decrease route readability when requirements are complex:
 
         return $routes;
 
-.. version-added:: 4.1
+.. versionadded:: 4.1
     The feature to inline requirements was introduced in Symfony 4.1.
 
 To learn about other route requirements - like HTTP method, hostname and dynamic
@@ -466,7 +466,7 @@ placeholder:
     To give a ``null`` default value to any placeholder, add nothing after the
     ``?`` character (e.g. ``/blog/{page?}``).
 
-.. version-added:: 4.1
+.. versionadded:: 4.1
     The feature to inline default values was introduced in Symfony 4.1.
 
 Listing all of your Routes