Show authors/maintainers in documentation and error messages

[Luthaf]

We started recording this information in #145, we should now use it.

Here are all the places I think we should use this:

• in the documentation for this architecture
• to create an error message in case of exception during training, asking to report the issue & tag the maintainers (can we generate an URL to do this & automatically add the relevant architecture tag?)
• to record inside the model metadata