[Docs] API docs folder in the openapi client README does not exist.

The folder, https://github.com/rigetti/qcs-api-client-rust/tree/main/qcs-api-client-openapi/docs, which is referenced in the [README](https://github.com/rigetti/qcs-api-client-rust/blob/main/qcs-api-client-openapi/README.md) is missing along with the associated files.

The links in the page are broken as a result of this.