Add Documentation for Adding a New Recipient

[mcdonnnj]

💡 Summary

Add instructions to the README that outline the steps to add a new recipient for data exported by the cyhy-data-extract.py script.

Motivation and context

Myself and @dav3r had to spend a non-trivial amount of time figuring out what needed to be changed to add a new party as a recipient for the regular extracts run in production. It would be good to have it clearly documented both for future use as well as clearly documenting it for completeness.

Implementation notes

Directions should include starting from a blank slate in terms of configuration. All requirements and steps to perform this action should be outlined.

Acceptance criteria

• Directions created in README
• Someone is able to perform the expected action following the given directions