[Docs] Use 1-2-3 list for deploy steps in deployment/frameworks/ (#24633)

Signed-off-by: windsonsea <haifeng.yao@daocloud.io>

docs/deployment/frameworks/haystack.md

@@ -6,7 +6,7 @@ It allows you to deploy a large language model (LLM) server with vLLM as the bac
 
 ## Prerequisites
 
-- Setup vLLM and Haystack environment
+Set up the vLLM and Haystack environment:
 
 ```bash
 pip install vllm haystack-ai
@@ -14,13 +14,13 @@ pip install vllm haystack-ai
 
 ## Deploy
 
-- Start the vLLM server with the supported chat completion model, e.g.
+1. Start the vLLM server with the supported chat completion model, e.g.
 
-```bash
-vllm serve mistralai/Mistral-7B-Instruct-v0.1
-```
+    ```bash
+    vllm serve mistralai/Mistral-7B-Instruct-v0.1
+    ```
 
-- Use the `OpenAIGenerator` and `OpenAIChatGenerator` components in Haystack to query the vLLM server.
+1. Use the `OpenAIGenerator` and `OpenAIChatGenerator` components in Haystack to query the vLLM server.
 
 ??? code