Allow opening multiple windows

[ghost]

Is your feature request related to a problem? Please describe. Pretty much every browser (gemini or not) support opening multiple windows for side by side use or for organization purposes.

Describe the solution you'd like A new Ctrl+N keyboard shortcut and an option in the header bar to open a new window, while also an option in the context menu of a link to open it in new window.

Describe alternatives you've considered

Additional context