Install fzf and its key bindings via Homebrew per the instructions here https://github.com/junegunn/fzf
Install bat so fzf can preview files all pretty n' stuff: https://github.com/sharkdp/bat
Read https://junegunn.kr/2016/07/fzf-git/ to learn about how this works. Look over junegunn's scripts here: https://gist.github.com/junegunn/8b572b8d4b5eddd8b85e5f4d40f17236