Is your feature request related to a problem? Please describe.

Reader view has a toggle icon to display or add the feeds sidebar. Other views don’t have this option.

Use case

No response

Describe the solution you’d like

Add this feature to all views, including views created by extensions. It can always be useful to get extra space at times, whichever the view.

Describe alternatives you’ve considered

When the sidebar is hidden, I’d also suggest to add management/add buttons in the toolbar, since they are also hidden.

Additional context

By the way this button as it is implemented currently in Reader view isn’t accessible: it doesn’t have a title mostly, so it’s hard to guess what the button is about.