Update config doc to document storing creds in a secret (#628)
Update config doc to document storing creds in a secret (#628)

* Update config doc to document storing creds in a secret

* Add file instructions

* Include message about namespace

* Include Dune references for creds

eriknelson/ansible-service-broker,eriknelson/ansible-service-broker,rthallisey/ansible-service-broker,johnkim76/ansible-service-broker,rthallisey/ansible-service-broker,johnkim76/ansible-service-broker,rthallisey/ansible-service-broker,eriknelson/ansible-service-broker,johnkim76/ansible-service-broker