message: Sphinx replace deprecated add_stylesheet with add_css_file
diff: @@ -152,7 +152,7 @@ html_sidebars = {
  #html_theme_path = []
  def setup(app):
  - app.add_stylesheet('theme_overrides.css')
  + app.add_css_file('theme_overrides.css')
  # The name for this set of Sphinx documents. If None, it defaults to
  # "<project> v<release> documentation".
  