Update release doc, upcoming release doc

Change-Id: Ibce6bd1f7eef5b8757b51d66503dd42a98c16fd7
diff --git a/index.rst b/index.rst
index 20fec6b..ac11b63 100644
--- a/index.rst
+++ b/index.rst
@@ -129,4 +129,5 @@
    :glob:
 
    release/1*
+   release/upcoming.rst
    release/process.rst