Switching the order of "Instructor Checkout" and "How we operate"

### How could the content be improved?

I am offering a suggestion that it could make more sense to teach the [How we operate](https://carpentries.github.io/instructor-training/instructor/15-carpentries.html) section before the [instructor training checkout](https://carpentries.github.io/instructor-training/instructor/14-checkout.html) section.
The reason being that we introduce jargon, the process for organizing, and the roles available with the carpentries in how we operate, and that leads nicely into the concrete steps to becoming an instructor.

Start by reviewing the linked “How we operate” and “Instructor Training Checkout” sections and the lesson navigation that places them in sequence. Done means “How we operate” appears before “Instructor Training Checkout” in the training flow.

Written by the indexing model from the issue text.