Updated existing functions which took a pointer for structs, now take a
reference instead for ease of access and avoiding the use of parameter
as optional.
Added fullscreen functionality - togglable.
- feature works by directly resizing the currently focused window.
- terminal window can be toggled between fullscreen and original size.
- if multiple windows exist, then exiting fullscreen will cause all
windows to be organised, essentially placing the focused fullscreen
window back into its original tiling placement.
