[docs] remove primary sidebar from tutorial (#2142)

* remove primary sidebar from tutorial

* lint

docs/conf.py

@@ -195,7 +195,7 @@ def setup(app):
 # html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-# html_sidebars = {}
+html_sidebars = {"tutorial": []}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.