Enable sphinx_rtd_theme for read the docs

Author: xispa

docs/conf.py

@@ -17,6 +17,7 @@
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.viewcode',
+    'sphinx_rtd_theme',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -87,7 +88,7 @@
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = 'default'
+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