Linting and updated docs.

Author: domdfcoding

README.rst

@@ -152,3 +152,9 @@ To install with ``conda``:
 		$ conda install consolekit
 
 .. end installation
+
+Additionally, for better support, install `psutil <https://pypi.org/project/psutil/>`_ by specifying the ``terminals`` extra:
+
+.. code-block:: bash
+
+	$ python -m pip install consolekit[terminals]

consolekit/terminal_colours.py

@@ -125,9 +125,7 @@
 
 def resolve_color_default(color: ColourTrilean = None) -> ColourTrilean:
 	"""
-	Internal helper to get the default value of the color flag. If a
-	value is passed it's returned unchanged, otherwise it's looked up from
-	the current context.
+	Helper to get the default value of the color flag.
 
 	If a value is passed it is returned unchanged,
 	otherwise it's looked up from the current context.

consolekit/utils.py

@@ -27,18 +27,22 @@
 #
 
 # stdlib
+import contextlib
 import difflib
 import os
 import sys
 from functools import lru_cache
 from itertools import cycle
 from types import ModuleType
-from typing import IO, List, Sequence
+from typing import IO, Callable, ContextManager, List, Sequence
 
 # 3rd party
 import click
 from domdf_python_tools.import_tools import discover, discover_entry_points
 from domdf_python_tools.stringlist import StringList
+from domdf_python_tools.words import SANS_SERIF_ITALIC_LETTERS
+from mistletoe import block_token, span_token  # type: ignore
+from mistletoe.base_renderer import BaseRenderer  # type: ignore
 
 # this package
 from consolekit.terminal_colours import Colour, Cursor, Fore, Style, code_to_chars