[Docs] Have a try to improve frameworks/streamlit.md

[windsonsea]

• use steps in deploy section
• add a command to prepare the vllm env
• add alt text to image

[gemini-code-assist]

Code Review

This pull request significantly improves the Streamlit integration documentation by adding explicit installation steps, restructuring the deployment guide into a numbered list, and improving image accessibility with alt text. My feedback focuses on further enhancing the clarity of the setup process by consolidating all dependency installations into a single step within the Prerequisites section. This change will create a more intuitive and error-resistant guide for users.

[DarkLight1337]

Thanks, LGTM