In [Contributing.md](https://github.com/compiler-research/xeus-cpp/blob/main/CONTRIBUTING.md) file, under the general-guidelines section [Project Jupyter Contributor Documentation](https://github.com/compiler-research/xeus-cpp/blob/main/CONTRIBUTING.md#general-guidelines) is pointing to [this link](https://jupyter.readthedocs.io/en/latest/contributor/content-contributor.html) that shows 404 Not Found