I'm comfortable with hjkl now and thus this is not useful anymore since
it also disables them in command mode where I actually need them from
time to time.
When TERM is not xterm-256color (for example in st or tmux) t_8f and
t_8b have to be set manually for colors to work.
Add XDG_CONFIG_HOME/vim to packpath so that plugins work.
Since the vim plugins are stored in submodules and vim-plug is not a big
fan of that when installing (Needs PlugClean and PlugInstall again
although the repos of the plugins were already pulled) it makes more
sense to me to use vim8s native plugin management.
Use vim-plug to load onedark instead of the two files in
vim/{autoload,colors}. This enables to update the theme and have it as a
submodule in the rep.
