Add version info for os.kill and signal changes from #1220212.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index e5e00d0..6777196 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1735,6 +1735,8 @@
    will be set to *sig*. The Windows version of :func:`kill` additionally takes
    process handles to be killed.
 
+   .. versionadded:: 2.7 Windows support
+
 
 .. function:: killpg(pgid, sig)