Add tmux config and bring back Neovim

Tmux config seems like it probably solved things. Wondering if I outta
put a line in there to automatically source the tmux config. Still can't
believe I've went this long without needing to muck with the tmux config
at all. I wonder how life will be different now, hopefully better.

install

@@ -23,7 +23,7 @@ else
   git pull origin main
 fi
 
-stow git screen vim zsh
+stow git screen tmux vim zsh
 
 if [[ `uname` == Darwin ]]; then
   stow macos