Write a GTN Style Guide

Including
- how to structure
- how to e.g. tell people to run workflows (maybe it should just be a snippet though?)
- best practices
- tips level of detail to go into

Start by reviewing the existing GTN training materials and compare their structure, workflow instructions, best practices, and level of detail. Done means publishing a style guide that addresses each listed topic and resolves whether workflow instructions should use a reusable snippet.

Written by the indexing model from the issue text.