doc: Change default theme to sphinx_rtd_theme

Author: eugmes

doc/conf.py

@@ -91,7 +91,7 @@
 
 # The theme to use for HTML and HTML Help pages.  Major themes that come with
 # Sphinx are currently 'default' and 'sphinxdoc'.
-html_theme = 'sphinxdoc'
+html_theme = 'sphinx_rtd_theme'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the