fix sense_resistor description (#524)

Specifying the sense resistor as "motor" dependant confuses people as it is a driver spec, not a motor spec.

docs/Config_Reference.md

@@ -4034,7 +4034,7 @@ run_current:
 #   The amount of time (in seconds) to wait after changing homing current.
 #   The default is 0.5 seconds.
 sense_resistor:
-#   The resistance (in ohms) of the motor sense resistor. This
+#   The resistance (in ohms) of the driver sense resistor. This
 #   parameter must be provided.
 #stealthchop_threshold: 0
 #   The velocity (in mm/s) to set the "stealthChop" threshold to. When
@@ -4145,7 +4145,7 @@ run_current:
 #   The amount of time (in seconds) to wait after changing homing current.
 #   The default is 0.5 seconds.
 sense_resistor:
-#   The resistance (in ohms) of the motor sense resistor. This
+#   The resistance (in ohms) of the driver sense resistor. This
 #   parameter must be provided.
 #stealthchop_threshold: 0
 #   The velocity (in mm/s) to set the "stealthChop" threshold to. When
@@ -4271,7 +4271,7 @@ run_current:
 #   The amount of time (in seconds) to wait after changing homing current.
 #   The default is 0.5 seconds.
 sense_resistor:
-#   The resistance (in ohms) of the motor sense resistor. This
+#   The resistance (in ohms) of the driver sense resistor. This
 #   parameter must be provided.
 #idle_current_percent: 100
 #   The percentage of the run_current the stepper driver will be
@@ -4496,7 +4496,7 @@ run_current:
 #   The amount of time (in seconds) to wait after changing homing current.
 #   The default is 0.5 seconds.
 sense_resistor:
-#   The resistance (in ohms) of the motor sense resistor. This
+#   The resistance (in ohms) of the driver sense resistor. This
 #   parameter must be provided.
 #stealthchop_threshold: 0
 #   The velocity (in mm/s) to set the "stealthChop" threshold to. When