Configure the stale bot (#7108)
Configure the stale bot (#7108)

* Configure the stale bot.

* Add top level comment.

* except assignees

* Give warning about closing issues.
stweil/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,letsencrypt/letsencrypt,stweil/letsencrypt,lmcro/letsencrypt