Migrate Linux tool/dependencies installation to use Homebrew about dotfiles HOT 1 CLOSED

#38 added Homebrew to the Linux installation process in scripts/setup-shell.bash. With this now installed, we should migrate as much on the Linux setup over to Homebrew as possible to simplify the cross-platform nature of this repo.

Areas of concern are:

• navi uses fzf underneath, I am unsure how the brew installed fzf interacts with navi vs the native/manual fzf
• Homebrew's deps require native OS installation methods, creating some divergence

Tools installable via Homebrew:

• asdf
• fzf
• z
• starship terminal theme
• zsh
• unzip

This should allow the deletion of a decent amount of code and forking behaviour as we will rely on Homebrew to log if something is already installed or not

from dotfiles.