feature #3659 [Internals] Complete notification description for kernel.terminate (bicpi)

This PR was merged into the 2.3 branch.

Discussion
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[Internals] Complete notification description for kernel.terminate

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | -

Commits
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7e09e82 [Internals] Complete notification description for kernel.terminate

Author: weaverryan

book/internals.rst

@@ -172,7 +172,10 @@ Event):
 #. Listeners of the ``kernel.response`` event can manipulate the ``Response``
    (content and headers);
 
-#. The Response is returned.
+#. The Response is returned;
+
+#. Listeners of the ``kernel.terminate`` event can perform tasks after the
+   Response has been served.
 
 If an Exception is thrown during processing, the ``kernel.exception`` is
 notified and listeners are given a chance to convert the Exception to a
@@ -367,6 +370,8 @@ The FrameworkBundle registers several listeners:
 ``kernel.terminate`` Event
 ..........................
 
+*Event Class*: :class:`Symfony\\Component\\HttpKernel\\Event\\PostResponseEvent`
+
 The purpose of this event is to perform "heavier" tasks after the response
 was already served to the client.