Make it possible to group / add hierarchy for the slide preview panel.

[tikurahul]

Slides are typically grouped into sections. It would be nice if we could group previews that way as well.

• Add some indentation in slide previews that belong to a group so its visually clear which group a slide preview belongs to.
• Add a floating group name / or show group name on hover. Room to experiment with UX.
• Add the ability to expand and collapse entire sections.
• Add a clear line of seperation between sections.

I don't mind taking this on, but I wanted to make sure this makes sense as a feature request first.

[nyblnet]

Yes, please, and thanks for offering. Sections are a real gap, and your sketch is a good starting point.

Two things that would help it land smoothly:

• Start with the format. Sections need a small addition to the deck format, so a short proposal first (here or in a draft PR) of how they are stored would be great. It needs to be additive, so older files open unchanged and an older app ignores sections cleanly, and slide ids and the interactive states that hang off a slide need to stay as they are.
• Keep it in the sidebar. Present mode, print and PowerPoint export can ignore sections at first, and we can follow up.

Happy to review as soon as you have something.