WIP set of configuration and macros to enable running the ERCF on RRF
Add M98 P"ercf/lib/init.g" to the bottom of config.g
Edit ercf/settings.g to configure the drive assignments (M584).
Stepper motor configuration, M569, can be done in config.g or
ercf/settings.g
In order to run these macros, RRF 3.4b4 or newer must be used
Many variables can be configured in ercf/settings.g, reference
ercf/lib/globals.g to see what can be altered.