In DM-12687 we moved the original stack package template to a `stack_package_legacy` directory of https://github.com/lsst/templates. But this still isn’t the right long-term home for that content because it isn’t a true template.

This ticket is to create a new repo in https://github.com/lsst-dm called pybind11_example that can house the content. The Developer Guide pages that reference this material will be updated to point there.