[Info][main] Correct the mistake in information documents (#4157)

### What this PR does / why we need it?
Correct the mistake in information documents

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?
ut

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

---------

Signed-off-by: lilinsiman <lilinsiman@gmail.com>

docs/source/community/versioning_policy.md

@@ -1,4 +1,4 @@
-# Versioning policy
+# Versioning Policy
 
 Starting with vLLM 0.7.x, the vLLM Ascend Plugin ([vllm-project/vllm-ascend](https://github.com/vllm-project/vllm-ascend)) project follows the [PEP 440](https://peps.python.org/pep-0440/) to publish matching with vLLM ([vllm-project/vllm](https://github.com/vllm-project/vllm)).