Example for Prusa MK3S and MK3.  
It includes macros (I noticed most other examples don't) but some of these are needed for the filament sensor as well as to restore the Tram Z/ Calibrate Z functionality. I also really wanted something that would work fully out-of-the-box with all Prusa default gcode and even with a UI like Mainsail.   
Explicitly put the Prusa USB-to-serial issue note in there as well as workarounds based on feedback by Arksine. 
My normal config is just this with the appropriate options uncommented for my BMG, 0.9-degree stepper Prusa, and then my PID, mesh, and IS along with an extra optional macro or two.
Explicitly confirmed this version loads without error in latest Klipper.

Whitespace fixes.