Add line_dash to style_tt

[debruijne]

Add style_tt(i = ..., line = "tblr", line_width = .., line_dash = "")
In tabularray there are the options solid, dashed or dotted. In the stroke: (dash: ) argument in Typst these options have the same names (solid, dashed or dotted), although in Typst there are more options ("densely-dotted", "loosely-dotted", "densely-dashed", "loosely-dashed", "dash-dotted", "densely-dash-dotted", "loosely-dash-dotted").
CSS border-style property also has solid, dashed, dotted.
Just support for the three overlapping options solid, dashed and dotted would be great! But if it's just a pass through then all Typst styles can be supported and it just breaks in other formats, which is fine for me.

style_tt(i = 2, line = "t", line_dash = "dashed")
would output hline{2} = {dashed} or \hline[dashed] for LaTeX tabularray.
Or line(stroke: (dash: "dashed")), in Typst.

Thanks for this great typst supporting package!

For reference see:
https://typst.app/docs/reference/visualize/stroke/#constructor-dash
Or 1.8 Hlines and vlines and 2.2 Hlines and vlines
https://ctan.math.illinois.edu/macros/latex/contrib/tabularray/tabularray.pdf

[vincentarelbundock]

Thanks a lot for the suggestion!

I think it is interesting, but I'm really trying to implement features only when we can support them in nearly all of the output formats. And here the difficulty might be HTML. That's because currently the bottom lines are implemented as filled blocks, and AFAIK those can't be dashed. The reason we use this hack is that sometimes we want to have lines with trim, or fractional size, and other minor things.

We can probably relax that, but it is likely to be some work, and it would require great care when looking at the website examples and golden tests (screenshots).

I'd be happy to consider a PR for this, but we'd need to be sure the HTML displays nicely.

Also maybe line_type= instead of line_dash= since the latter is one of the types, not all.