Add documentation for using copilot

[cmungall]

https://docs.github.com/en/copilot/how-tos/agents/copilot-coding-agent/troubleshooting-copilot-coding-agent

This was suggested by others such as @caufieldjh but I didn't realize that it would work.

It turns out things may be easier than this https://ai4curation.github.io/aidocs/how-tos/set-up-github-actions/ -- and an API key is not even needed

All you need to do is make sure the scripts (obo-grep, obo-checkin, and obo-checkout) are available in the repo, and copilot will use them

obophenotype/uberon#3582

Multiple models are possible

Can be configured either by environment or mcps
https://docs.github.com/en/copilot/how-tos/agents/copilot-coding-agent/best-practices-for-using-copilot-to-work-on-tasks#pre-installing-dependencies-in-github-copilots-environment

cc @justaddcoffee @matentzn @sabrinatoro @dosumis @kltm

[cmungall]

Exploring this with @kltm

So it looks like only Pro users are able to assign copilot to review or make PRs, OR the org needs to subscribe to enterprise. This, Pro is available if you can prove you are .edu, and even if you can't it is cheap, so a good fallback option