[docs] Diffusion pipeline (#12148)

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Author: stevhliu

docs/source/en/_toctree.yml

@@ -9,11 +9,11 @@
   - local: stable_diffusion
     title: Basic performance
 
-- title: DiffusionPipeline
+- title: Pipelines
   isExpanded: false
   sections:
   - local: using-diffusers/loading
-    title: Load pipelines
+    title: DiffusionPipeline
   - local: tutorials/autopipeline
     title: AutoPipeline
   - local: using-diffusers/custom_pipeline_overview