CSS change for documentation to make the content area a bit wider relative to the window; PEP 8

docs/source/conf.py

@@ -131,6 +131,7 @@ html_theme_path = [better_theme_path]
 # documentation.
 if html_theme == 'better':
     html_theme_options = {
+        'cssfiles': ['_static/pgpy_better.css'],
         'sidebarwidth': '19rem',
     }