Bed Auto Leveling feature

Check the Readme for instruction how to enable and configure the feature

Marlin/stepper.cpp

@@ -969,6 +969,14 @@ long st_get_position(uint8_t axis)
   return count_pos;
 }
 
+#ifdef ENABLE_AUTO_BED_LEVELING
+float st_get_position_mm(uint8_t axis)
+{
+  float steper_position_in_steps = st_get_position(axis);
+  return steper_position_in_steps / axis_steps_per_unit[axis];
+}
+#endif  // ENABLE_AUTO_BED_LEVELING
+
 void finishAndDisableSteppers()
 {
   st_synchronize();