LaTeX output using tabularray

[baptiste]

I recently discovered the tabularray package for LaTeX(3), which is very ambitious features-wise. It might be a little too bleeding-edge for a default option for Latex output, but it might be worth considering for implementing fancier formatting options not currently achievable with tabu/booktabs/longtable etc. I particularly like its key-value syntax for options, which leaves the array body untouched, and is therefore much easier to program (no mixing between content and formatting). Here's an example I had to produce (it's ugly because it needs to match some Word formatting, but relatively hard to reproduce in Latex)