List sidebars to avoid errors looking for template 't'

Author: jaraco

docs/conf.py

@@ -2,4 +2,4 @@
 # Custom sidebar templates, maps document names to template names.
 html_theme = 'alabaster'
 templates_path = ['_templates']
-html_sidebars = {'index': 'tidelift-sidebar.html'}
+html_sidebars = {'index': ['tidelift-sidebar.html']}