[diffusion] doc: consolidate documentation (#21373)

docs/diffusion/performance/cache/index.md

@@ -1,6 +1,6 @@
-# Caching Acceleration for Diffusion Models
+# Caching Acceleration
 
-SGLang provides multiple caching acceleration strategies for Diffusion Transformer (DiT) models. These strategies can significantly reduce inference time by skipping redundant computation.
+SGLang provides two complementary caching strategies for Diffusion Transformer (DiT) models. Both reduce denoising cost by skipping redundant computation, but they operate at different levels.
 
 ## Overview
 
@@ -11,8 +11,6 @@ SGLang supports two complementary caching approaches:
 | **Cache-DiT** | Block-level | Skip individual transformer blocks dynamically | Advanced, higher speedup |
 | **TeaCache** | Timestep-level | Skip entire denoising steps based on L1 similarity | Simple, built-in |
 
-
-
 ## Cache-DiT
 
 [Cache-DiT](https://github.com/vipshop/cache-dit) provides block-level caching with
@@ -54,6 +52,13 @@ See [teacache.md](teacache.md) for detailed documentation.
 
 For Flux and Qwen models, TeaCache is automatically disabled when CFG is enabled.
 
+```{toctree}
+:maxdepth: 1
+
+cache_dit
+teacache
+```
+
 ## References
 
 - [Cache-DiT Repository](https://github.com/vipshop/cache-dit)