Fix outdated use of summary_prompt in tutorial.

[ekzhu]

In the tutorial page: https://microsoft.github.io/autogen/docs/tutorial/conversation-patterns

There are several examples of using summary_prompt however the code is outdated as summary_prompt is not the top-level argument anymore, it should be:

{
    "recipient": group_chat_manager_with_intros,
    "summary_method": "reflection_with_llm",
    "summary_args":  {"summary_prompt": "Summarize the sequence of operations used to turn " "the source number into target number."},
},

Would you like to help fixing this?

Originally posted by @ekzhu in #2621 (comment)

[pk673]

@ekzhu I would love to work on this, could you please assign this to me. thanks!

[ekzhu]

@pk673 just assigned. Thanks!