To install just run the install script:
$ ./install.sh
To get all features working properly make sure you change your terminal font to hack (installed locally by the install.sh).
On iterm2 (OS X) I use Hack Nerd Font 14pt as font (anti-aliased).
Also make sure you are using xterm-256color as your TERM. You can do that by adding the following line to your ~/.zshrc or ~/.bashrc:
export TERM=xterm-256color
Hack fonts are downloaded from https://github.com/source-foundry/Hack and the "Nerd Font" version from https://github.com/ryanoasis/nerd-fonts/tree/master/patched-fonts/Hack/Regular/complete.
This font setup also supports powerlevel10k (zsh theme).