Add option to generate a "quick reference guide" table in doc-generator

For the documentation generator, it would be nice to have a table (appendix, or even a standalone document) that lists out each schema and its current (latest) version, perhaps with links to a publication URI.  If this was implemented as a separate function that could be inserted anywhere in the document using a directive like the `[add_toc]` reference, it would allow a lot of flexibility for use.