add warning to 5.0 document

Change-Id: I86fcf4f16a5929ccf2590b54eacc15d44c8bb150
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..6a8f36f
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,6 @@
+[gerrit]
+host=gerrit.opencord.org
+port=29418
+project=mcord.git
+defaultremote=origin
+defaultbranch=cord-5.0