A page on how to publish to and how to administer StartSCH

Explain the model and give examples:
- Tanfolyam:
- `Page` Kir-Dev, `Category` Tanfolyam, `Event` Tanfolyam 2026, `Post`s: information and reminders
- ask the people to follow the event on StartSCH on external platforms, like email and other social media
- Kajas korok:
- `Page` Langosch, `Category` Nyitasok, `Post`s: same as the current emails, mark as private, delete after a while

The issue does not name a documentation file or entry point. Locate the project's existing documentation and the relevant Page, Category, Event, and Post administration guidance, then use the Tanfolyam and Kajas korok examples as the checklist; done means the publishing and administration process is explained with both examples.

Written by the indexing model from the issue text.