[latexrefman-discuss] Add descriptions of built-in LaTeX classes

[Karl Berry]

    Subject: [latexrefman-discuss] Adjust About and Overview sections to
    Nodes: About this document, Overview
    ...
    Subject: [latexrefman-discuss] Add descriptions of built-in LaTeX classes
    Node changed: Document classes

Installed both (with a little tinkering that I couldn't resist).
Thanks Jim!  --karl