Add More Typographic Elements: Footnotes, Sidenotes, Textboxes, Multi columns, Lig­a­tures, Quotations, Tables, Figures, etc

[bnjmnrsh]

As per Tachyons #678

Is it possible to add more typographic elements like:
Footnotes,
Endnotes,
Sidenotes,
Textboxes,
Multi columns,
Lig­a­tures,
Quotations,
Tables,
Figures,
etc.
Ref:

https://www.gwern.net/Sidenotes
https://danilafe.com/blog/sidenotes/
https://latex.js.org/
https://www.pagedjs.org/

[bnjmnrsh]

Some of these fall into the category of components, and so are out of scope for the base of Tachyons-haru, however there are a few exceptions, that could be optional add ons:

mulitcol
Lig­a­tures: font-variant-ligatures