docs: set rtd html_theme.

docs/conf.py

@@ -348,9 +348,9 @@
 # on_rtd is whether we are on readthedocs.org, this line of code grabbed from docs.readthedocs.org
 on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
 
-if not on_rtd:  # only import and set the theme if we're building docs locally
-    import sphinx_rtd_theme
-    html_theme = 'sphinx_rtd_theme'
-    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+#if not on_rtd:  # only import and set the theme if we're building docs locally
+import sphinx_rtd_theme
+html_theme = 'sphinx_rtd_theme'
+html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # otherwise, readthedocs.org uses their theme by default, so no need to specify it