Change the first letter to uppercase (#4375)

### What this PR does / why we need it?
 The first letter  of the English title should be capitalized
### Does this PR introduce _any_ user-facing change?
no
### How was this patch tested?
ut

- vLLM version: v0.11.0
- vLLM main:
vllm-project/vllm@2918c1b

Signed-off-by: herizhen <[email protected]>
Co-authored-by: herizhen <[email protected]>

Author: herizhen

docs/source/user_guide/feature_guide/kv_pool_mooncake.md

@@ -26,7 +26,7 @@
 **load_async**:Whether to Enable Asynchronous Loading. The default value is false.  
 **register_buffer**:Whether to Register Video Memory with the Backend. Registration is Not Required When Used with MooncakeConnectorV1; It is Required in All Other Cases. The Default Value is false.
 
-## run mooncake master
+## Run Mooncake Master
 
 ### 1.Configure mooncake.json