Allow accessing other article features from Iceberg

[ronilaukkarinen]

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

I should be able to access setting up featured article image, excerpt and other things that live inside editor without having to exit Iceberg editor. I'd like to create everything on Iceberg. Now I have to exit Iceberg to add photos, tags, category and excerpt after completing the actual writing process.

Describe the solution you'd like

Add some minimal menu to a corner that opens up these features in minimal manner. Do not include other less useful stuff that Gutenberg includes.

Describe alternatives you've considered

A modal or hotkey if possible.