In order to make applications honor your custom settings, create
a symlink to `~/.config/fontconfig/conf.avail/nn-foo.conf` in
`~/.config/fontconfig/conf.d`, e.g.:

  $ cd ~/.fontconfig/conf.d
  $ ln -f -s ../conf.avail/60-latin.conf .

Pay attention to the . <dot> in the second command.


