Add information to the PR body submitted by trestle-bot

[jpower432]

Is your feature request related to a problem? Please describe.

When PRs are submitted by trestle-bot. The PR body is not configurable. Only the PR title is configurable. There should be enough information in the PR body for the user to understand where the PR came from.

Describe the solution you'd like

• Add a basic text to the PR body to link to the trestle-bot website

Describe alternatives you've considered
Make the PR body configurable, but since trestle-bot should be aware of the changes being submitted, this does not seem needed.

Additional context
N/A