* Keyboard settings
Debian's =console-setup= package provides =setupcon=, a neat utility
that reads XKB settings from =/etc/default/keyboard= and translates
them to whatever format the Linux console understands.

To get something similar to =ctrl:nocaps= on distros that do not
feature this utility:
#+begin_src sh
$ localectl | grep "VC Keymap"  # To spot the current KEYMAP.
$ sudo mkdir -p /usr/local/share/kbd/keymaps
# KEYMAPS_DIR: depending on the distro:
# - /usr/share/kbd/keymaps/xkb
# - /lib/kbd/keymaps/xkb
$ gunzip --stdout ${KEYMAPS_DIR}/${KEYMAP}.map.gz   |
    sed 's/^keycode 58 = .*$/keycode 58 = Control/' |
    sudo tee /usr/local/share/kbd/keymaps/${KEYMAP}-nocaps.map
# In /etc/vconsole.conf, change KEYMAP to ^this^ absolute filename.
# Reboot.
#+end_src