[Feature] Keyboard shortcut for focusing display

[LiberQuack]

First of all, awesome job on this project :). It's amazing how a single developer built this app.

As I am using it, I felt it would be very helpful to split focus mode into:

• Focus triggered by head movement
• Focus triggered by keyboard shortcuts

The reasoning for that is, some times you are already seeing a good portion of the unfocused display, but to really trigger it you have to move your head a considerable amount

Maybe having a shortcut like Meta Ctrl Arrow-Right would help us save our neck even more The arrows would allow an experience similar to navigating menus