Link to instructor no-show policy

In the [How to Organise a Carpentries Workshop Locally](https://carpentries.github.io/instructor-training/15-carpentries.html#how-to-organise-a-carpentries-workshop-locally) section we reference the [instructor no-show policy](https://docs.carpentries.org/handbooks/instructors.html#instructor-training-attendance-policy). This links to the no-show policy for attending Instructor Training but it seems like it's meant to reference the no-show policy for instructors teaching a workshop.

Start with the “How to Organise a Carpentries Workshop Locally” section in the linked instructor-training page and compare its no-show policy link with the instructor handbook. Confirm which policy covers instructors teaching a workshop, update the link, and verify that the reference no longer points to the Instructor Training attendance policy.

Written by the indexing model from the issue text.