Brief overview of PR changes/additions

This PR addresses issue by adding a “Video Guide” button to the generic mapper interface. Clicking this button will open a web page with a video explanation of how to set up the generic mapper script.

Motivation for adding to Mudlet

It’s been requested a few times, and it would be really handy to link people to a video explanation of how the generic mapper script should be setup.

Other info (issues closed, discussion etc)

/fixes #3172 /claim #3172 Video link: https://youtu.be/m6nqwbvEJXc?si=px9Abm1CsU-UXRkJ