* Implement cells bin
* Temporarily keep cells source
* Send complete bin entries from session to clients when a cell gets removed
* Polish styles
* Hydrate bin entries on section deletion as well
* Show all sections and enable cross-section focus navigation
* Move focus to the client
* Add shortcut for evaluating all cells
* Fix and expand tests
* Make section links scroll to the given section
* Virtualize output lines
* Remove unused dependency
* Remove VirtualizedLinesComponent
* Pass lines as HTML nodes and use as template
* Validate hook children
* Refactor markup