Match each lesson with a parallel 'going further' #19
Description
In #17, @FrankMittelbach suggests that we want a clear 'beginners' route for the site, but that we might also want a parallel/complementary 'more info' route. I wonder if we could do that by having a second set of files, say called going-further-<n>.md. They could then have 'additional details', so for #8 the idea of \newcolumntype or \hline or \multirow, for #1 perhaps some of the history, etc.
Does this seem like a good idea? Once we have the content, each main lesson could then have a 'Want more - see the further details' link.