codereview.cfg: add

Change-Id: I6dffe939ed9666a48991690e2e2e38a5546b079b
diff --git a/codereview.cfg b/codereview.cfg
new file mode 100644
index 0000000..3f8b14b
--- /dev/null
+++ b/codereview.cfg
@@ -0,0 +1 @@
+issuerepo: golang/go