[Lint]Style: reformat markdown files via markdownlint (#5884)

### What this PR does / why we need it?
reformat markdown files via markdownlint

- vLLM version: v0.13.0
- vLLM main:
bde38c11df

---------

Signed-off-by: root <root@LAPTOP-VQKDDVMG.localdomain>
Signed-off-by: MrZ20 <2609716663@qq.com>
Co-authored-by: root <root@LAPTOP-VQKDDVMG.localdomain>

benchmarks/scripts/perf_result_template.md

@@ -10,6 +10,7 @@
 {serving_tests_markdown_table}
 
 ## Offline tests
+
 ### Latency tests
 
 - Input length: 32 tokens.