WIP on schema documentation
More progress on schema documentation
Finishing up initial draft of user documentation for schemas.  Still need to add 'API' docs for individual schemas, but for the most part they won't be that useful *until* and unless I write a custom sphinx extension for displaying them.
Filled out the API docs a bit
Initial version of the API docs. Not terribly useful yet as it does not display what is checked by the actual schemas.  Eventually a custom sphinx extension for this purpose may be in order but maybe not until the format is more nailed down.
Add initial support for lists of allowed values as the docs suggest are possible