add AutoBuild feature

[davidxwwang]

there is an AutoBuild feature on the 0.2 branch( https://microsoft.github.io/autogen/0.2/blog/2023/11/26/Agent-AutoBuild/), and I want to add this feature

[ekzhu]

Thanks! You can create PR for this as part of the extension modules.

[davidxwwang]

ok