Add a simple example for how to Integrate an event dispatcher for createUrl in another module which alters the result of the URL that is built.

Problem/Motivation

This event was added to the module
✨ Integrate an event dispatcher to allow other modules to alter the result URL built Fixed

It would be helpful for others to know how to use it. We should add an easy example and reference to it in the facets_pretty_paths README.md file

Steps to reproduce

see
✨ Integrate an event dispatcher to allow other modules to alter the result URL built Fixed

Proposed resolution

Add to our documentation

Remaining tasks

Review documentation/example changes.