whatsnew: epoll supports with.

Also reworded the description of the feature in the docs.
diff --git a/Doc/whatsnew/3.4.rst b/Doc/whatsnew/3.4.rst
index 4a097d2..5b68243 100644
--- a/Doc/whatsnew/3.4.rst
+++ b/Doc/whatsnew/3.4.rst
@@ -851,6 +851,15 @@
 (Contributed by Christian Heimes in :issue:`16595` and :issue:`19324`.)
 
 
+select
+------
+
+:class:`~select.epoll` objects now support the context management protocol.
+When used in a :keyword:`with` statement, the :meth:`~select.epoll.close`
+method will be called automatically at the end of the block.  (Contributed
+by Serhiy Storchaka in :issue:`16488`.)
+
+
 shelve
 ------