readme: public-inbox -> numen
sxhkd: env -C -> cd  for busybox
zsh: tweak ls options for busybox, ls -> \ls
shell: /usr/bin -> /bin
readme: numenvoice.com -> numenvoice.org
sxhkd: add alternative Super+Enter keybindings
urxvt: use monospace and support changing the size
use a capital letter for Tiles
manpage: mention /usr/local/bin/tiles
sxhkd: support custom config files
zsh: fix env var typos
install: split out ./install-shell.sh
bump copyright years
menu: restyle code
sxhkd: fix Super+=
tweak PACKAGES comments
overhaul readme and manpage intro, add screenshot