Fix more ja documents for LuaTeX/XeTeX + systemF

Fix more ja documents for LuaTeX/XeTeX + systemF

I used the following command inside the ja directories, and
confirmed the diff manually:

  git ls-files -z | xargs -0 sed -i -e 's/\\font_typewriter "default" "default"/\\font_typewriter "default" "IPAGothic"/'

These changes are consistent with 6656dd22.