doc: flake8 and doc8

pybricks/_instances.py

@@ -4,6 +4,7 @@ from .builtins import Speaker, Display, Battery, ColorLight, KeyPad, LightArray
 
 from types import ModuleType
 
+
 def make_instance(classdef):
     """Make a class instance to look like a module so Sphinx can parse it."""
     name = ''
@@ -13,6 +14,7 @@ def make_instance(classdef):
             setattr(mod, m.__name__, m)
     return mod
 
+
 light = make_instance(ColorLight)
 
 lights = make_instance(LightArray)