Add description to model attributes

[consolethinks]

Is your feature request related to a problem? Please describe.
The SciCat API has a list of data exchange models with good general descriptions for their purpose. However, their attributes have little to no description, and while most of them are evident in their purpose, some would require a description in order to properly utilize them. For example, the size attribute of dataset doesn't say in what units should we communicate the size of the dataset, or what exactly is the difference between sourceFolder and sourceFolderHost.

Describe the solution you'd like
Some resource that would describe what exactly is the purpose of either all or just the less obvious attributes in models. These descriptions could be placed for example in the Swagger UI templates.

Describe alternatives you've considered
A separate site for describing these models and their attributes, for which API endpoints they're used and how.

Additional context

Maybe a good place to add descriptions to the attributes (possibly these would have to be duplicated to all endpoints dealing with the same model)