Design lessons to embed Quarto slides

[oharac]

Embed a Quarto slide deck in the top of each lesson for easy access and version control (rather than Google slides currently, without links)

[oharac]

Unfortunately, it looks like the Quarto book doesn't render files the same way a Quarto website does (though the documentation says it should) - so in a website, ALL .qmds are rendered automatically whether they show up in the _quarto.yml, but in a book, only those referenced in _quarto.yml get rendered. See quarto-dev/quarto-cli#10531.

If files are rendered and placed manually in the docs portion of the built book, it works fine - but there is not a good way to automate that manual placement - hold off til the issue gets fixed on the Quarto side