Range adjustment on RANALOG=ON

[LipefipeFelps]

The Nuclear Throne Mobile issue on the compatibility list says that you should disable the crosshair, since it doesn't work. It actually does work when you activate RANALOG=ON in keys.ini, but the radius looks like this

So the aim will pretty much go to the corners, making it almost useless. The idea is to implement a variable that makes it so you can change the radius, and make it something like this

It would help not only in this game, but in pretty much all games with those kind of controls. Thanks in advance.