extruder: Deprecate old extruder commands and shared_heater config option

Deprecate SET_EXTRUDER_STEP_DISTANCE and SYNC_STEPPER_TO_EXTRUDER.
Recommend using SET_EXTRUDER_ROTATION_DISTANCE and
SYNC_EXTRUDER_MOTION.

Deprecate the extruder "shared_heater" option and reocmmend using
extruder_stepper config sections to obtain the same functionality.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/kinematics/extruder.py

@@ -150,6 +150,7 @@ class PrinterExtruder:
         if shared_heater is None:
             self.heater = pheaters.setup_heater(config, gcode_id)
         else:
+            config.deprecate('shared_heater')
             self.heater = pheaters.lookup_heater(shared_heater)
         # Setup kinematic checks
         self.nozzle_diameter = config.getfloat('nozzle_diameter', above=0.)