Create emails_from_url.py (#1756)

* Create emails_from_url.py

* Update emails_from_url.py

* Update emails_from_url.py

* 0 emails found:

* Update emails_from_url.py

* Use Python set() to remove duplicates

* Update emails_from_url.py

* Add type hints and doctests

Co-authored-by: vinayak <itssvinayak@gmail.com>
Co-authored-by: Christian Clauss <cclauss@me.com>