update doc

Author: yiyixuxu

docs/source/en/_toctree.yml

@@ -89,8 +89,8 @@
 - sections:
   - local: modular_diffusers/developer_guide
     title: Developer Guide
-  - local: modular_diffusers/overview
-    title: Overview
+  - local: modular_diffusers/quicktour
+    title: Quicktour
 - sections:
   - local: using-diffusers/cogvideox
     title: CogVideoX