Improvement for Joystick and Force Feedback section

[Hiran Chaudhuri <hiran.chaudhuri@gmx.net>]

Hello there,

I am neither developer nor committer on the linux kernel. But trying to
figure out the kernel support for my Microsoft Sidewinder Force
Feedback 2 joystick I found two things that might get improved in the
kernel documentation. Maybe someone could update it with below
information:

1)
https://www.kernel.org/doc/html/latest/input/joydev/joystick.html#microsoft-sidewinder-joysticks
The Microsoft Sidewinder Force Feedback 2 joystick is not listed at
all, but after playing around I was able to make it work. So it makes
sense to extend the list with that model.

2) https://www.kernel.org/doc/html/latest/input/ff.html#does-it-work
When trying fftest it is important to use the correct device node
/dev/input/eventXX. Unfortunately I was fiddling for a long time with
the wrong node (it may even change depending on the hot-plugging of the
USB devices).

Therefore first run the command `evtest`, which scans all
/dev/input/event* nodes and will print the devices found. From that
pick the correct file, then run `fftest`.

Also the command `ffcfstress` is a very nice test to verify the
joystick works.

Best regards

Hiran