[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>

docs/source/quick_start.md

@@ -3,6 +3,7 @@
 ## Prerequisites
 
 ### Supported Devices
+
 - Atlas A2 training series (Atlas 800T A2, Atlas 900 A2 PoD, Atlas 200T A2 Box16, Atlas 300T A2)
 - Atlas 800I A2 inference series (Atlas 800I A2)
 - Atlas A3 training series (Atlas 800T A3, Atlas 900 A3 SuperPoD, Atlas 9000 A3 SuperPoD)
@@ -140,7 +141,7 @@ vllm serve Qwen/Qwen2.5-0.5B-Instruct &
 
 If you see a log as below:
 
-```
+```shell
 INFO:     Started server process [3594]
 INFO:     Waiting for application startup.
 INFO:     Application startup complete.
@@ -183,7 +184,7 @@ vLLM is serving as a background process, you can use `kill -2 $VLLM_PID` to stop
 
 The output is as below:
 
-```
+```shell
 INFO:     Shutting down FastAPI HTTP server.
 INFO:     Shutting down
 INFO:     Waiting for application shutdown.