Add a dropdown arrow to hide nested segments

[mateuszbugaj]

The timer component gets long quickly when working with nested segments. We can add a dropdown arrow similar to the one used by Obsidian for bullet point lists to hide or show sub-segments.

Here's a demo of how that might look like.

I would also like to hide an entire list of segments to make notes less cluttered, but I think that might be a separate issue since there needs to be a change in the overall layout of the component. What do you think?

[YomuKaigen]

I often only desire to see the total duration, the ability to hide/collapse segments would help me keep my different trackers on the same page with predictable sizes. Ideally, with the option to keep things collapsed when a new segment is added.