[Idea] Git integration: use Co-Authored-By trailer

[crabmusket]

There's a convention in git commit messages to use a Co-Authored-By trailer to denote commits made by multiple authors.

https://github.blog/news-insights/product-news/commit-together-with-co-authors/

Here's an example where I did it manually in a repo I'm working on:

And the expanded commit:

I'd be happy to contribute an option to have Aider commit with this convention, if people want this.

It does raise the question of what email address to use. I picked [email protected]. However, it's unclear to me if there are security or other implications to pushing code to GitHub with this email address attached to commits.

Another option might be to allow me to configure an email address to attribute to Aider. Then, for example, I could use [email protected] as Aider's email when committing to my own repos.