Notebook on web crawling (#2720)

* Web crawling with Spider

* reset run count

* spell correction

* crawl agent

* reset execution counters

* correct return types

* metadat for website

* format

* Update notebook/agentchat_webcrawling_with_spider.ipynb

Co-authored-by: Eric Zhu <[email protected]>

* Update website/docs/Examples.md

Co-authored-by: Eric Zhu <[email protected]>

* Update agentchat_webcrawling_with_spider.ipynb

* Update agentchat_webcrawling_with_spider.ipynb

Co-authored-by: Eric Zhu <[email protected]>

---------

Co-authored-by: Chi Wang <[email protected]>
Co-authored-by: Qingyun Wu <[email protected]>
Co-authored-by: Eric Zhu <[email protected]>