Enhanced accessibility

CaseyB,

I changed the script to use an event/delegate system, and refactored things to match C# conventions. I also added instructions to the readme for those who need it. I've tested my modifications and they worked perfectly. I can't say as much for any of the other magnet slider detection scripts out there.

I hope this finds you well, and that you agree these changes will help others to use the magnet sensor.

Thanks,
 - Max