talks: add codereview.cfg

See golang.org/cl/4131 for context.

Change-Id: Icaed1dad1fe77a35b3c8c1a8a3782686493155cb
Reviewed-on: https://go-review.googlesource.com/7749
Reviewed-by: David Crawshaw <crawshaw@golang.org>

codereview.cfg

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