[Translation] added logging capability.

| Q             | A
| ------------- | ---
| Doc fix?	 | no
| New docs? | yes(symfony/symfony/pull/10887)
| Applies to | 2.6+
|Fixed tickets |	-
	
Let's add a link to the new spot in the reference section. That way, people can see this is for debug mode only by default, but they can configure it.