Convert site to Quarto

[ethanwhite]

Jekyll was the state of the art static site generator when I first developed this course, but it is increasingly out of date and folks are unfamiliar with how to work with it. Quarto is well suited to this content, allows executing code blocks, and is gaining wide adoption in the data science community. It will make it easier for others to engage with the course materials. It seems like a natural move, but I'd be happy to hear feedback on the upsides/downsides of making this change.

This is a major task since we have a number of custom liquid templates that are used to assemble content in various forms. These will need to be converted to EJS templates for use with Quarto's custom listings. As we're doing this it is also time to consider whether there are any design simplifications that can be implemented to make customizing the site easier.

If anyone is interested in helping out with this conversion, or thinks the conversion is a bad idea, please let me know.