Add typst support (#31)

[elipousson]

Added support based on the examples/documentation here: https://typst.app/project/rQwGUWt5p33vrsb_uNPR9F

The ensure_typst_font_awesome function is copied from quarto-cli (I was unsure if there is someway to reuse it without creating it again) https://github.com/quarto-dev/quarto-cli/blob/312912c165a51f82f8fd0ba6b5f8e6f850294a90/src/resources/filters/customnodes/callout.lua#L665-L671

[cderv]

@elipousson Getting into this PR now.

If that is ok, I may split the work you did in several steps:

• First, it would be good to bring typst support with feature parity with HTML and LaTeX. Currently they use FA 6.7.2. Update to FA7 may come later (Update to FontAweome 7 #44). So I would like to only the FA6 support in the typst package.

• They also use regular (solid being the default). I have a new example.qmd that shows the different support we need for typst too.

• Then, you added support for color, which is not yet supported for other. There was discussion about it in FR: add color argument? #23 and one unmerged PR Added support for color (?) #35. So I would wait for a decision before adding support. Also, styling in Quarto is a synomyn of theming and brand.yml, so we would probably need to make this work, too.

So overall, I'll do some modifications based on your work if that is ok.

[cderv]

Correct me if I am wrong, but for now the Typst support you did in this PR requires to have the fontawesome fonts installed on the system right ?

Usage mentions to install the font: https://typst.app/universe/package/fontawesome#usage

I think we need to resolve the problem of making the font available through the extensions... 🤔

Though from my reworked PR it seems to work somehow 🤔

[cderv]

This PR is superseded by

• Add Typst support with feature parity to HTML and LaTeX PDF #45