Document where to set `KISYS3DMOD` about kicadstepupmod HOT 2 CLOSED

There should be documentation on which panel to adjust, rather than just sending users to "Preferences"

@xobs
the doc could be improved, but:

1. the user should read it (at page 1) after the phrase: "your KISYS3DMOD value into the FreeCAD StepUp preferences page, located in the preferences system of FreeCAD (Edit menu -> Preferences)."
   you can see "Just click the green icon: [kSU icon]"
2. the user should spend some time in reading the docs ... at page 10) you can see an image of the main kSU preferences
   Preferences Page: "Preferences Page for configuring main parameters"

I will be pleased to accept PR for improving the docs... source of the cheatsheet pdf here:
https://github.com/easyw/kicadStepUpMod/blob/master/demo/kicadStepUp-cheat-sheet.odg
source file in LibreOffice format

An other note, that is related to FreeCAD use:
to find (show) a workbench preference page, you first need to load the workbench in FreeCAD.

from kicadstepupmod.

to find (show) a workbench preference page, you first need to load the workbench in FreeCAD.

Thanks! It was the last bit that was missing from the documentation. I've updated the documentation to reflect this, since I really was scratching my head over it.

from kicadstepupmod.