add copy to clipboard feature for quarto tables

[bricegnichols]

We need a simple way to copy tables into spreadsheets. I think we can have a small button that copies contents to the clipboard. I imagine using this mostly for RTP work, but would probably be a useful standard in a class we use to generate tables for all notebooks.

[Joanneylin]

produce a download button:

https://fmmattioni.github.io/downloadthis/articles/downloadthis.html

[bricegnichols]

@Joanneylin, does your link above work in python? If not, I wonder if this would work? https://stackoverflow.com/questions/73138448/does-the-copy-code-to-clipboard-option-exist-in-r-markdown