Starship font support

[yndajas]

Issue

The script installs Starship (via the Brewfile), which by default has a Nerd Font prerequisite, but the script doesn't cover this. Without it, various icons that Starship uses to represent technologies like Git will appear as question mark boxes

Solutions

Option 1: mostly automatic

• Extend the Brewfile to include font installation via Homebrew (installing the Nerd Font version of something like Fira Code, Hack, Meslo or Source Code Pro)
• Update the guide to instruct people to update their terminal emulator to use the installed font

Option 2: manual

Update the guide to instruct people to:

• install a Nerd Font by their chosen means
• update their terminal emulator to use the installed font

[erbridge]

I like either option 1 but automating the font settings or dropping Starship in favour of something else. The aim of this script is to be as low interaction as possible, and for something like a prompt, I don't think it's worth leaving people with required follow up actions they need to take for the thing to be useful.