Flexible Rate Limit Resets for Codex and a method to get a Reset

@VeitB Thanks for looking into this, I have had similar frustrations. Do us a favor though, please consider renaming this post to smth that doesn’t use the ambiguous term “plus”. Or at least not “codex plus”. Codex plus is obviously a thing… Thanks, and keep 'em on their toes! Peace from your friendly Irish grammar-casual-observer, Paul, living in Heidelberg