[Performance] Mention Symfony Stowatch in some doc sections

Author: javiereguiluz

performance.rst

@@ -211,21 +211,24 @@ deployment process too):
 
 .. _profiling-applications:
 
-Profiling Applications
-----------------------
+Profiling Symfony Applications
+------------------------------
+
+Profiling with Blackfire
+~~~~~~~~~~~~~~~~~~~~~~~~
 
 `Blackfire`_ is the best tool to profile and optimize performance of Symfony
 applications during development, test and production. It's a commercial service,
 but provides free features that you can use to find bottlenecks in your projects.
 
+Profilwing with Symfony Stopwatch
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 Symfony provides a basic performance profiler in the development
 :ref:`config environment <configuration-environments>`. Click on the "time panel"
 of the :ref:`web debug toolbar <web-debug-toolbar>` to see how much time Symfony
 spent on tasks such as making database queries and rendering templates.
 
-Custom Profiling
-~~~~~~~~~~~~~~~~
-
 You can measure the execution time and memory consumption of your own code and
 display the result in the Symfony profiler thanks to the `Stopwatch component`_.