Streamline the "How templates work" section in the Actor output schema page

[janbuchar]

Even after #2197, it is still difficult to understand what the template URLs actually change in the Run result view - how the properties map to output tabs, etc.

The examples first show a page of code snippets, and only then we get a small screenshot, where it's not really clear what changed. Perhaps we could show the screenshot first? Or more of them, or a gif/video...