feat: customize window margins

[MKrabs]

Is your feature request related to a problem? Please describe. When the window > Gap size is too small, the windows overlap with the "hide top bar" extension and the auto hiding Dock at the bottom, causing them to hide.

Describe the solution you'd like New settings to add custom margins to add some space at the top / bottom / left / right (in px)

Describe alternatives you've considered Setting the gap size to 16 shrinks the windows enough for the top bar to appear again. Setting the gap size to 16 (multiplier 3) shrinks the windows enough for the dock to appear again. --> I dont like these fixes, since the add gaps everywhere