gpt-4 support; openai workflow fix; model str; timeout; voting (#958)

* workflow; model str; timeout

* voting

* notebook

* pull request

* recover workflow

* voted answer

* aoai

* ignore None answer

* default config

* note

* gpt-4

* n=5

* cleanup

* config name

* introduction

* readme

* avoid None

* add output/ to gitignore

* openai version

* invalid var

* comment long running cells