New CommonMark implementation: The Markdown Package for TeX

In case we are keeping a list, there is a new implementation of CommonMark available. Namely, the Markdown Package for TeX has complied with CommonMark since version 3.0.0-alpha, as discussed at the TUG 2023 conference in Bonn today, see also a recording.

@Vit_Novotny There is a list which you can update yourself!

Thank you, I have updated the wiki.