[Task]: Add a Copilot Instructions File

### Describe the task

While each developer may have their own instructions, this repo should have specific instructions for Copilot to understand how to interpret, change, and test aspects of this project.

More information [here](https://docs.github.com/en/enterprise-cloud@latest/copilot/using-github-copilot/coding-agent/best-practices-for-using-copilot-to-work-on-tasks).