anchor: love.window.getFullscreenModes
  Gets a list of supported fullscreen modes.
  modes = love.window.getFullscreenModes( displayindex )
  displayindex (1) number The index of the display, if multiple monitors are available.
  modes table A table of width/height pairs. (Note that this may not be in order.)
  modes.width number Window fullscreen width.
  modes.height number Window fullscreen height.