Facilitate comments in GraphQL schema generation flow

**Is your feature request related to a problem? Please describe.**
The GraphQL schema that is generated has no comments/documentation. It does not suit inclusion into a well documented federated graph.

**Describe the solution you'd like**
A way to annotate dimensions such that the generated GraphQL types have _some_ degree of documentation.

**Describe alternatives you've considered**
Manual documentation post-generation. It does not suit our needs as we scale up