Pull requests via t3code should use a pull request template

[makeavish]

Currently, there is a single button that commits and then creates a pull request. However, this flow does not use a pull request template.

Pull requests should use a PR template so that contributors are prompted to provide consistent and relevant information (e.g., description of changes, type of change, testing steps, related issues) when opening a PR.

Suggested Fix

Add a pull request template (.github/pull_request_template.md) and ensure the single-button "commit and create PR" flow populates the PR body using this template.

[n-hallberg]

I like the idea!

I also don't use the feature, because it somehow always adds to my PR description, that the tests and ci did not run. Which confuses the reviewers and is odd, because in the message above the agent clearly said, it was validated.

I think a template would help to steer the description meaningfully.