Add cookbook for blurring faces with hosted api

[NickHerrig]

Description

Added a supervision cookbook on how to blur faces with supervision, inference_sdk, and a model from roboflow universe.

• [X] New Supervision cookbook

How has this change been tested, please provide a testcase or example of how you tested the change?

This change has been tested in a google colab notebook, and was able to build locally with mkdocs serve