[Docs] Fix syntax highlighting of shell commands (#19870)

Signed-off-by: Lukas Geiger <lukas.geiger94@gmail.com>

docs/deployment/frameworks/open-webui.md

@@ -7,13 +7,13 @@ title: Open WebUI
 
 2. Start the vLLM server with the supported chat completion model, e.g.
 
-```console
+```bash
 vllm serve qwen/Qwen1.5-0.5B-Chat
 ```
 
 1. Start the [Open WebUI](https://github.com/open-webui/open-webui) docker container (replace the vllm serve host and vllm serve port):
 
-```console
+```bash
 docker run -d -p 3000:8080 \
 --name open-webui \
 -v open-webui:/app/backend/data \