I build these with a wrapper around CommonMark. Try:
deps/from-tar.sh layer-cmark
And then:
build/doc.sh all-markdown
The output HTML shows up in _release/VERSION/doc.
See doc-toolchain.md for details.
osh.1 is a man page written using
the mdoc macro language for the troff
(groff) formatter.
You can view it with man doc/osh.1.