> Ideally, with sed/awk, or better in C. "Parsing" HTML with sed is simply wrong.
You need to use a decent HTML parsing library, as parsing HTML is complex.There is https://github.com/yujiahaol68/downmark that uses Go html library, but I have not tried it.
Seriously though, if you are not going to convert HTML to markdown every day and you are not building a long-term solution, just use pandoc.