Fix syntax issues

Author: javiereguiluz

components/http_kernel.rst

@@ -511,7 +511,7 @@ as possible to the client (e.g. sending emails).
 .. _component-http-kernel-kernel-exception:
 
 9) Handling Exceptions: the ``kernel.exception`` Event
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 **Typical Purposes**: Handle some type of exception and create an appropriate
 ``Response`` to return for the exception

frontend.rst

@@ -111,4 +111,3 @@ Other Front-End Articles
 .. _`Turbo`: https://turbo.hotwired.dev/
 .. _`Symfony UX`: https://ux.symfony.com
 .. _`API Platform`: https://api-platform.com/
-.. _`PostCSS`: https://postcss.org/