- Updated example to show behavior
- Created styles for Expander and ExpanderRow
- Simpler implementation of `ExpanderRow`
- Deleted `ExpanderData` and replaced it with `ExpanderRow`
- Every row can now have child rows.
- Ran cargo fmt.
- Deleted settings example
- Added expander to cosmic example
- Expander icons now render
ListBox partially implemented
- Created new widget `scrollbar` which can adopt COSMIC styling.
- Increased sidebar icon size by 4 pixels to improve visibility.
- Added padding inside the navigation bar to prevent collision with the scrollbar.
- Increased the max width of the condensed navbar for the scrollbar.
