Antora expects content to be in a particular file system organization, with component descriptors at specified locations. (done)
Antora only deals with .adoc files, so .md and .mdtext files need to be converted. For the content I'm considering including this is done, although manual editing is still needed. I believe some of the 7.0 and possibly 7.1 examples documentation is still in .md form. I'm proposing to not include this; if there's a decision to include it, this content can also be converted.
Intra-site links need to be converted to xrefs using antora page coordinates. This can be automated for "link:' links. I'm discovering many other styles. (I've fixed the ones that I can recognize; I think there are a lot more)
There are a lot of asciidoc syntax mistakes in the existing content, most of them errors in section levels. This is easy but tedious to fix. (I've started this)