docs: Clarify and enhance run_demo_loop utility documentation for beginners

[UmmeHabiba1312]

This Pull Request aims to improve the clarity and user-friendliness of the run_demo_loop utility documentation. While the existing description is accurate, this update refines it to be more accessible for new users and beginners.

Key improvements in this update:

• Expanded Description: The introductory text now provides a clearer explanation of run_demo_loop's purpose and its benefit for quick, interactive testing.
• Enhanced Code Comments: The Python example is now annotated with simple comments that guide the user through each part of the code, explaining what the Agent is and how the loop is started.
• Structured Explanation: The description of how run_demo_loop works is reorganized into a more readable and easy-to-digest paragraph. It clearly explains key features like prompting for input, maintaining conversation history, and real-time streaming of output.
• Clear Exit Instructions: The method for exiting the loop is presented in a straightforward manner.

These changes make the documentation more engaging and effective for developers new to the SDK, helping them get started with agents and interactive testing with minimal friction.

I believe this is a valuable documentation improvement that will enhance the overall developer experience.

[seratch]

if you revert the changes for this file, this pull request looks good to me.

[UmmeHabiba1312]

I've reverted the changes to that file. Let me know if anything else needs to be updated.
Thanks again for reviewing!