Added default width and height
Added default width and height

If the screen resolution is higher than the supported
resolutions from Bing, then this will set a default
width and height determined by defaults set for
desktop versus mobile.

UtkarshGpta/bing-desktop-wallpaper-changer,UtkarshGpta/bing-desktop-wallpaper-changer,nks15/bing-desktop-wallpaper-changer,nks15/bing-desktop-wallpaper-changer