Fix for nested lists rendering in Material

* `mkdocs_material_nested_lists_rendering_fix` introduces a fix for better
  rendering of nested lists in the Material theme as suggested here:
  <https://github.com/squidfunk/mkdocs-material/issues/508>.

Dockerfile

@@ -5,5 +5,7 @@ COPY requirements.txt .
 RUN pip install -r requirements.txt
 COPY mkdocs_configuration /usr/local/bin/
 RUN chmod 755 /usr/local/bin/mkdocs_configuration
+COPY mkdocs_material_nested_lists_rendering_fix /usr/local/bin/
+RUN chmod 755 /usr/local/bin/mkdocs_material_nested_lists_rendering_fix
 COPY mkdocs_configuration_lib.py /usr/local/bin/
 COPY mkdocs_configuration_tests.py /usr/local/bin/

mkdocs_material_nested_lists_rendering_fix

+#!/usr/local/bin/python
+# -*- coding: utf-8 -*-
+"""
+MkDocs Material theme fix for nested lists rendering.
+<https://github.com/squidfunk/mkdocs-material/issues/508>
+"""
+
+import click
+import os
+import sys
+
+import mkdocs_configuration_lib as lib
+
+
+@click.command()
+def main(
+):
+    """MkDocs Material theme fix for nested lists rendering."""
+
+    # Read the existing configuration from `mkdocs.yml`.
+    configuration = lib.read_configuration()
+
+    # If no configuration was found do nothing and exit successfully
+    # and silently.
+    if not configuration:
+        sys.exit(0)
+
+    # Make sure the configuration includes the `theme`, otherise exit
+    # successfully and silently.
+    theme = configuration.get('theme')
+    if theme is None:
+        sys.exit(0)
+
+    # Make sure the theme configuration includes the `name` and the name is
+    # `material`, otherise exit successfully and silently.
+    theme_name = theme.get('name')
+    if theme_name is None or theme_name != 'material':
+        sys.exit(0)
+
+    # Create the `stylesheets` directory in the documentation directory if it
+    # doesn't already exist.
+    try:
+        os.mkdir(os.path.join(lib.DOCUMENTATION_DIRECTORY, 'stylesheets'))
+    except FileExistsError:
+        # Since the `stylesheets` directory already existed, check if a
+        # `material_nested_lists_rendering.css` file also existed already.
+        # If yes, exit successfully and silently.
+        if os.path.isfile(os.path.join(
+            lib.DOCUMENTATION_DIRECTORY,
+            'stylesheets',
+            'material_nested_lists_rendering.css'
+        )):
+            sys.exit(0)
+
+    # Create the appropriate stylesheet file.
+    with open(os.path.join(
+        lib.DOCUMENTATION_DIRECTORY,
+        'stylesheets',
+        'material_nested_lists_rendering.css'
+    ), 'w') as file_object:
+        file_object.write('\n'.join([
+            'article ul ul {',
+            '  list-style-type:  circle !important;',
+            '}',
+            '',
+            'article ul ul ul {',
+            '  list-style-type:  square !important;',
+            '}',
+        ]))
+
+    # Get the `extra_css` from the configuration. If it's not there get it as
+    # an empty list.
+    extra_css = configuration.get('extra_css', [])
+    # Append the recently created file `material_nested_lists_rendering.css`
+    # to the `extra_css` list.
+    extra_css.append(os.path.join(
+        'stylesheets',
+        'material_nested_lists_rendering.css'
+    ))
+    # Update the configuration with the updated `extra_css` list.
+    configuration.update({'extra_css': extra_css})
+
+    # Write the updated configuration to `mkdocs.yml`.
+    lib.write_configuration(configuration)
+
+
+if __name__ == '__main__':
+    main()