config: add classlink directive

We have index pages for most modules now, which link to individual classes. It is helpful if these empty class headers are hyperlinks. This commit does just that.

For most sensors/devices so far this is not really necessary as the images are already hyperlinks. But this will become more useful as we start adding index pages like these for classes without images, such as parameters.

doc/api/hubs/index.rst

@@ -13,43 +13,37 @@
    primehub
    ev3brick
 
-.. class:: MoveHub
-    :noindex:
+.. pybricks-classlink:: MoveHub
 
 .. figure:: ../../api/images/movehub.png
     :height: 10 em
     :target: movehub.html
 
-.. class:: CityHub
-    :noindex:
+.. pybricks-classlink:: CityHub
 
 .. figure:: ../../api/images/cityhub.png
     :height: 10 em
     :target: cityhub.html
 
-.. class:: TechnicHub
-    :noindex:
+.. pybricks-classlink:: TechnicHub
 
 .. figure:: ../../api/images/technichub.png
     :height: 10 em
     :target: technichub.html
 
-.. class:: PrimeHub
-    :noindex:
+.. pybricks-classlink:: PrimeHub
 
 .. figure:: ../../api/images/primehub.png
     :height: 10 em
     :target: primehub.html
 
-.. class:: InventorHub
-    :noindex:
+.. pybricks-classlink:: InventorHub
 
 .. figure:: ../../api/images/inventorhub.png
     :height: 10 em
     :target: primehub.html
 
-.. class:: EV3Brick
-    :noindex:
+.. pybricks-classlink:: EV3Brick
 
 .. figure:: ../../api/images/ev3brick.png
     :height: 10 em

doc/api/iodevices/index.rst

@@ -16,8 +16,7 @@
    dcmotor
    ev3devsensor
 
-.. class:: PUPDevice
-    :noindex:
+.. pybricks-classlink:: PUPDevice
 
 .. figure:: ../../api/images/sensor_pup.png
    :width: 70 %
@@ -25,43 +24,37 @@
 
    This class is only available on Powered Up hubs.
 
-.. class:: I2CDevice
-    :noindex:
+.. pybricks-classlink:: I2CDevice
 
 .. figure:: ../../api/images/sensor_rj12_bluegreen.png
    :width: 25 %
    :target: i2cdevice.html
 
-.. class:: UARTDevice
-    :noindex:
+.. pybricks-classlink:: UARTDevice
 
 .. figure:: ../../api/images/sensor_rj12_gray.png
    :width: 25 %
    :target: uartdevice.html
 
-.. class:: AnalogSensor
-    :noindex:
+.. pybricks-classlink:: AnalogSensor
 
 .. figure:: ../../api/images/sensor_rj12_brown.png
    :width: 25 %
    :target: analogsensor.html
 
-.. class:: LUMPDevice
-    :noindex:
+.. pybricks-classlink:: LUMPDevice
 
 .. figure:: ../../api/images/sensor_rj12_green.png
    :width: 25 %
    :target: lumpdevice.html
 
-.. class:: DCMotor
-    :noindex:
+.. pybricks-classlink:: DCMotor
 
 .. figure:: ../../api/images/rcxmotor.png
    :width: 40 %
    :target: dcmotor.html
 
-.. class:: Ev3devSensor
-    :noindex:
+.. pybricks-classlink:: Ev3devSensor
 
 .. figure:: ../../api/images/sensor_ev3dev.png
    :width: 70 %

doc/api/pupdevices/index.rst

@@ -20,78 +20,67 @@
    light
    remote
 
-.. class:: DCMotor
-    :noindex:
+.. pybricks-classlink:: DCMotor
 
 .. figure:: ../../api/images/pupdcmotors_label.png
     :width: 70 %
     :target: dcmotor.html
 
-.. class:: Motor
-    :noindex:
+.. pybricks-classlink:: Motor
 
 .. figure:: ../../api/images/pupmotors_label.png
     :width: 100 %
     :target: motor.html
 
-.. class:: TiltSensor
-    :noindex:
+.. pybricks-classlink:: TiltSensor
 
 .. figure:: ../../api/images/sensor_tilt.png
    :width: 35 %
    :target: tiltsensor.html
 
-.. class:: InfraredSensor
-    :noindex:
+.. pybricks-classlink:: InfraredSensor
 
 .. figure:: ../../api/images/sensor_proximity.png
    :width: 35 %
    :target: infraredsensor.html
 
-.. class:: ColorDistanceSensor
-    :noindex:
+.. pybricks-classlink:: ColorDistanceSensor
 
 .. figure:: ../../api/images/sensor_colordistance.png
    :width: 32 %
    :target: colordistancesensor.html
 
-.. class:: PFMotor
-    :noindex:
+.. pybricks-classlink:: PFMotor
 
 .. figure:: ../../api/images/pfmotor.png
    :width: 95 %
    :target: pfmotor.html
 
-.. class:: ColorSensor
-    :noindex:
+.. pybricks-classlink:: ColorSensor
 
 .. figure:: ../../api/images/sensor_color.png
    :width: 32 %
    :target: colorsensor.html
 
-.. class:: UltrasonicSensor
-    :noindex:
+.. pybricks-classlink:: UltrasonicSensor
 
 .. figure:: ../../api/images/sensor_ultrasonic.png
    :width: 37 %
    :target: ultrasonicsensor.html
 
-.. class:: ForceSensor
-    :noindex:
+.. pybricks-classlink:: ForceSensor
 
 .. figure:: ../../api/images/sensor_force.png
    :width: 35 %
    :target: forcesensor.html
 
-.. class:: Light
-    :noindex:
+.. pybricks-classlink:: Light
 
 .. figure:: ../../api/images/light.png
    :width: 90 %
    :target: light.html
 
-.. class:: Remote
-    :noindex:
+.. pybricks-classlink:: Remote
 
 .. figure:: ../../api/images/pupremote.png
    :width: 50 %