Sort imports with isort

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

1 files changed, 2 insertions, 4 deletions

diff --git a/sphinx/builders/htmlhelp.py b/sphinx/builders/htmlhelp.py
index d30f9805a..642ae7da6 100644
--- a/sphinx/builders/htmlhelp.py
+++ b/sphinx/builders/htmlhelp.py
@@ -12,14 +12,12 @@
 import warnings
 from typing import Any, Dict
 
-from sphinxcontrib.htmlhelp import (
-    chm_locales, chm_htmlescape, HTMLHelpBuilder, default_htmlhelp_basename
-)
+from sphinxcontrib.htmlhelp import (HTMLHelpBuilder, chm_htmlescape, chm_locales,
+                                    default_htmlhelp_basename)
 
 from sphinx.application import Sphinx
 from sphinx.deprecation import RemovedInSphinx40Warning, deprecated_alias
 
-
 deprecated_alias('sphinx.builders.htmlhelp',
                  {
                      'chm_locales': chm_locales,