fix docs (mock builtin adafruit_pixelbuf) and requirements.txt

Author: Neradoc

docs/conf.py

@@ -23,7 +23,12 @@
 # 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", "digitalio", "board"]
+autodoc_mock_imports = [
+    "adafruit_bus_device",
+    "adafruit_pixelbuf",
+    "board",
+    "digitalio",
+]
 
 autodoc_default_flags = ["special-members", "members"]
 

requirements.txt

@@ -3,4 +3,5 @@
 # SPDX-License-Identifier: Unlicense
 
 adafruit-circuitpython-busdevice
+adafruit-circuitpython-pixelbuf
 Adafruit-Blinka