DM: maybe fix autodoc

docs/conf.py

@@ -18,7 +18,7 @@
 # Uncomment the below if you use native CircuitPython modules such as
 # digitalio, micropython and busio. List the modules you use. Without it, the
 # autodoc module docs will fail to generate with a warning.
-autodoc_mock_imports = ["adafruit_bus_device", "micropython"]
+autodoc_mock_imports = ["adafruit_bus_device", "micropython", "digitalio"]
 
 intersphinx_mapping = {'python': ('https://docs.python.org/3.4', None),'BusDevice': ('https://circuitpython.readthedocs.io/projects/busdevice/en/latest/', None),'Register': ('https://circuitpython.readthedocs.io/projects/register/en/latest/', None),'CircuitPython': ('https://circuitpython.readthedocs.io/en/latest/', None)}