Context

During ChatGPT Retrieval Plugin integration, we ran into build issues on Evergreen hosts. In this case, because the package failed to build from source (it required a library that wasn't available on the host) and no wheel was on PyPI. However, the requirement was actually optional. So just a one-line change to `pyproject.toml` did the trick.

I realized that we could easily get this working without requiring a pull-request (and acceptance) on the upstream simply by applying a git patch file. This is a common technique used by `conda package` maintainers, as they often have to build for a more broad set of scenarios than the original authors intended.

So, I added a mechanism to apply a collection of patches. This is done generically, and I believe will come in useful going forward.

Definition of done

Add instructions on how to add patches in the README.md. Refer to chatgpt as example.