TODOs for GTN Event Pages

We've merged GTN event pages (https://github.com/galaxyproject/training-material/pull/4890), but still had some ideas for enhancements down the line:

- [ ] support for multiple tracks in a program
- [ ] support for smorgasbord-like CYOA programs?
- [ ] support simply pointing to learning pathways for a program?
- [x] On tutorials that are being used, add a banner of "This is being taught in an upcoming course, sign up here" https://github.com/galaxyproject/training-material/pull/4963
- [ ] On topic pages show a box if any courses are teaching materials from a given topic
- [x] Copy button that copies a slack/toot formatted version (with emoji for cost/when/deadlines/etc)
- [x] announce newly added events via GTN news bot
- [ ] Automatically use archive links for past events?
- [ ] Google form to add event PR (maybe we import the 'course builder')
- [x] support for custom setup instructions

Review the merged GTN event-page work in PR #4890 and the unchecked enhancement ideas in this issue. Choose one item, define its acceptance criteria, and inspect the related event or topic-page behavior; done means that item is implemented and verified without leaving its scope ambiguous.

Written by the indexing model from the issue text.