Includes:

Added STM32CubIDE files
Fix for spindle enable
Fix for stepper_delay > 3.5us
More segments per line
More planner stages
Option for 64k or 128k eeprom (C8 vs CB parts - many C8 parts actually have 128k, some don't. If yours does not, you need to use teh 64k option to properly save settings.

Important Options

$50=1 -> Enable spindle output, normal mode (0=off, 2=invert)
$40=10000 -> Use 10khz base frequency for PWM

grbl32

Please refer to gnea/grbl for the core GRBL codes. Check the grbl32 WIKI page for more information