Plan diff

Foresee this solution before they approve it. Show what would change, and what they should expect, as a file tree of git-like red and green lines, as if the PR is ready and they are looking at the changes tab.

The page is for them or a product reader. They are not looking to deep-dive the code.

Mark each part of a file with a blue @@ section @@ line. Indent the way a diff would. Write a sentence when the behavior is the point. Write a short code line when that is easier to read than the sentence. Do not paste the surrounding implementation.

Copy template.html, fill every {{TOKEN}}, and open the page.