Documentation has problem when generate pdf in zh-tw(Chinese) version. There is tofu. So I think the solution is to add zh-tw fonts and theme.yml to let asciidoctor-pdf use when convert .adoc file.
The font I use is [[ https://github.com/googlefonts/noto-cjk | googlefonts/noto-cjk ]] . So there will be two font file in freebsd-doc like below.
1. freebsd-doc/shared/zh-tw/zh-tw-font/NotoSansCJKsc-VF.ttf
2. freebsd-doc/shared/zh-tw/zh-tw-font/NotoSansMonoCJKsc-VF.ttf