Feature: Add image of completed PR template for Guestbook

[BekahHW]

Suggested solution

One of the things we see a lot when reviewing the guestbook PRs is the PR form isn't filled out properly.

In the Getting Started Section of the Practical Application let's add a screenshot below the warning after the text of 11.

Here's what a completed Pull Request Template for the guestbook looks like. Make sure yours looks like this, with your unique information.

[pedaars]

.take
@BekahHW happy to pick this issue up

[BekahHW]

Thanks! @pedaars please take a look at our contributing guidelines to assign yourself the issue.