Did some routine cleanup, mostly just dropping old commented out stuff
and other crap that was no longer applicable. Finally fixed the issue
where entering the `.git` directory would throw an error.
Installed was running as `sh` and a bunch of crap was lit up as being wrong in
POSIX mode, so just changed it over to run via `bash`. Added TabNine to the vim
install and added the appropriate `vimrc` stuff for that. Also dropped some old
color toggling shit I'm not using anymore.
Was getting into some weird territory where ZSH syntax was creeping in.
Reworked to be a pure shell script and updated the install instructions to
reflect that. Also a small bit of additional clean up in there.
Fixes#24
