The Redshift package on Arch doesn't seem to add a service file anywhere
so we have to add one ourselves in our configuration directory.
Geoclue doesn't seem to want to play nice with Redshift right now, so I
used the manual setting to add Paris' coordinates.
Switching to Termite because URxvt has weird rendering issues when
resizing the font.
i3-sensible-terminal needs the TERMINAL environment variable to launch
our prefered terminal emulator with the Ctrl+d binding.
Bash and Zsh both need a hook to enable Termite to open another terminal
in the same directory with the Ctrl+Maj+t binding.