This is building on nice work by user pifty

In my attempt to port in these documents into the SDF wiki, I found that the html2dokuwiki converter left messes where the original docs had HTML anchors in headings. Also it didn't de-escape <, > which dokuwiki doesn't need escaped and doesn't render correctly in markup.

So in this repo, I'm adding fixes for the above. I will also add other fixes that are global.