Fix docs config for version side bar

Author: xylar

docs/conf.py

@@ -35,15 +35,16 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = ['sphinx.ext.autodoc',
-              'sphinx.ext.autosummary',
-              'sphinx.ext.intersphinx',
-              'sphinx.ext.mathjax',
-              'sphinx.ext.viewcode',
-              'sphinx.ext.napoleon']
-
-# Add any paths that contain templates here, relative to this directory.
-templates_path = ["_templates"]
+extensions = [
+    'sphinx_rtd_theme',
+    'sphinx_multiversion',
+    'sphinx.ext.autodoc',
+    'sphinx.ext.autosummary',
+    'sphinx.ext.intersphinx',
+    'sphinx.ext.mathjax',
+    'sphinx.ext.viewcode',
+    'sphinx.ext.napoleon'
+]
 
 autosummary_generate = True