Add version info for os.kill and signal changes from #1220212.
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
index 300c717..8ac7bee 100644
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -78,16 +78,18 @@
.. data:: CTRL_C_EVENT
The signal corresponding to the CTRL+C keystroke event.
-
Availability: Windows.
+ .. versionadded:: 2.7
+
.. data:: CTRL_BREAK_EVENT
The signal corresponding to the CTRL+BREAK keystroke event.
-
Availability: Windows.
+ .. versionadded:: 2.7
+
.. data:: NSIG