api/nxtdevices: add module

doc/api/index.rst

@@ -23,6 +23,7 @@ Intro
    hubs
    pupdevices
    ev3devices
+   nxtdevices
    iodevices
    parameters
    tools

doc/api/nxtdevices.rst

@@ -0,0 +1,10 @@
+:mod:`nxtdevices <pybricks.nxtdevices>` -- NXT Devices
+======================================================
+
+.. automodule:: pybricks.nxtdevices
+    :no-members:
+
+NXT Motor
+^^^^^^^^^^^^^^^^
+This motor works just like a LEGO MINDSTORMS EV3 Large Motor. You can use it in
+your programs using the :mod:`Motor <.ev3devices>` class.

pybricks/nxtdevices.py

@@ -0,0 +1,2 @@
+"""Use LEGO® MINDSTORMS® NXT motors and sensors with the EV3 brick."""
+