Improve contributing docs or automate tasks

We should lay out some more specific steps about which documentation to update, where, and how in our contributing docs + maybe PR template.

Even better: can we automate that?

Start by locating the repository's contributing documentation and PR template, then review how contributor steps are currently described. Define the specific documentation changes and determine whether any of the requested tasks can be automated; done should mean the workflow is explicit and any agreed automation is documented or implemented.

Written by the indexing model from the issue text.