This is for https://fedoraproject.org/wiki/Changes/ModularCompose

To create a module, a developer creates a modulemd metadata file (yaml) and submits it to the module-build-service. That service builds the module in koji, and enriches the metadata file with information about exactly how it was built (by specifying what git hashes were used, for example).

We would like to bake that processed metadata file into the repo that ultimately becomes a part of the compose, so end-users can inspect it, rebuild it, etc..