Adding upcoming release tab.

Change-Id: I303e60ed4b951c1917982e62290aa7bcd846b422
diff --git a/index.rst b/index.rst
index cc8c682..088537e 100644
--- a/index.rst
+++ b/index.rst
@@ -105,4 +105,5 @@
    :glob:
 
    release/1*
+   release/upcoming.rst
    release/process.rst