Add tools_calibrate (#446)

* Add tools_calibrate

Sourced from https://github.com/viesturz/klipper-toolchanger and updated for versatility and ease of use

* Add tools_calibrate to the status reference

docs/Config_Reference.md

@@ -5662,6 +5662,52 @@ cs_pin:
 #   above parameters.
 ```
 
+### ⚠️ [tools_calibrate]
+
+Multi-toolhead nozzle offset calibration, using a 3-axis nozzle contact probe such as
+[Zruncho3D's Nudge Probe](https://github.com/zruncho3d/nudge).
+
+```
+[tools_calibrate]
+pin:
+travel_speed: 20
+#   X and Y travel speed in mm/sec
+spread: 5
+#spread_x:
+#spread_y:
+#   X and Y travel distance around the probe
+#initial_spread:
+#initial_spread_x:
+#initial_spread_y:
+#   X and Y travel distance for the initial probe locating moves
+lower_z: 1.0
+#   Distance to lower in Z for contact with the sides of the probe
+speed: 2
+#   The speed (in mm/sec) to retract between probes
+lift_speed: 4
+#   Z Lift speed after probing
+final_lift_z: 6
+#   Z lift distance after calibration, must be greater than any
+#   height variance between tools
+trigger_to_bottom_z: 0.25
+#   Offset from probe trigger to vertical motion bottoms out.
+#   decrease if the nozzle is too high, increase if too low.
+#samples: 1
+#   The number of times to probe each point. The probed z-values will
+#   be averaged. The default is to probe 1 time.
+#sample_retract_dist: 2.0
+#   The distance (in mm) to lift the toolhead between each sample (if
+#   sampling more than once). The default is 2mm.
+#samples_result: average
+#   The calculation method when sampling more than once - either
+#   "median" or "average". The default is average.
+#samples_tolerance: 0.100
+#   The maximum Z distance (in mm) that a sample may differ from other
+#   samples. If this tolerance is exceeded then either an error is
+#   reported or the attempt is restarted (see
+#   samples_tolerance_retries). The default is 0.100mm.
+```
+
 ### [trad_rack]
 
 Trad Rack multimaterial system support. See the following documents from the

docs/G-Codes.md

@@ -1554,6 +1554,33 @@ The velocity argument is not available on CoreXY. With no arguments, this
 command responds with the movement direction with the most acceleration or
 velocity.
 
+### ⚠️ [tools_calibrate]
+
+The following commands are available when the
+[tools_calibrate config section](Config_Reference.md#tools_calibrate) is enabled.
+
+#### TOOL_CALIBRATE_QUERY_PROBE
+`TOOL_CALIBRATE_QUERY_PROBE`: Query the current calibration probe state.
+
+#### TOOL_LOCATE_SENSOR
+`TOOL_LOCATE_SENSOR`: Locate the sensor relative to the initial tool. The initial
+tool is the 0 offset, which other tools are calibrated against.
+
+Before running `TOOL_LOCATE_SENSOR`, position your primary toolhead centered over
+the calibration probe.
+
+#### TOOL_CALIBRATE_TOOL_OFFSET
+`TOOL_CALIBRATE_TOOL_OFFSET`: After locating the sensor with your initial tool,
+position each additional tool over the sensor and run `TOOL_CALIBRATE_TOOL_OFFSET`
+to find their offsets.
+
+#### TOOL_CALIBRATE_SAVE_TOOL_OFFSET
+`TOOL_CALIBRATE_SAVE_TOOL_OFFSET MACRO=<macro_name> VARIABLE=<variable_name> [VALUE="({x:0.6f}, {y:0.6f}, {z:0.6f})"]`:
+Save the last calibration result to a macro variable.
+
+`TOOL_CALIBRATE_SAVE_TOOL_OFFSET SECTION= ATTRIBUTE= [VALUE="{x:0.6f}, {y:0.6f}, {z:0.6f}"]`:
+Save the last calibration result to a field in your configuration. Calibration data saved this way will not take effect until after a `RESTART` of your printer.
+
 ### [trad_rack]
 
 The following commands are available when the

docs/Status_Reference.md

@@ -568,6 +568,15 @@ on a cartesian, hybrid_corexy or hybrid_corexz robot
 - `carriage_1`: The mode of the carriage 1. Possible values are:
   "INACTIVE", "PRIMARY", "COPY", and "MIRROR".
 
+## tools_calibrate
+
+The following information is available in the
+[tools_calibrate](Config_Reference.md#️-tools_calibrate) object:
+- `sensor_location`: Once calibrated, the location of the sensor
+- `last_result`: The last tool calibration result
+- `calibration_probe_inactive`: Status of the calibration probe as of
+  the last `TOOL_CALIBRATE_QUERY_PROBE`
+
 ## trad_rack
 
 The following informatin is available in the