Define referents for all packages
We want to support extra spack packages for softwares developed at Inria.
It makes sense to assign for each package a software developer, who is the most capable of providing an up-to-date version of the package with:
- the last releases, branches useful for their users
- convenient variants
- compatibility with underlying components
@all Please complete the table in the README to define who will be responsible for the support of each package.