chore: Update README with new setup instructions

[chookity-pokk]

This is mentioned in #154 and I figured it was probably a good idea to get this in the official README. All credit goes to
@Arnavion

[chookity-pokk]

Closes #154

[chookity-pokk]

Since this is just a documentation change I am going to merge without review.

[Arnavion]

You may want to keep the code fences because they make it clear where a command or command arg starts and ends.

[chookity-pokk]

You may want to keep the code fences because they make it clear where a command or command arg starts and ends.

@Arnavion Well shucks, looks like I should have waited for a review, so embarrassing. Thanks, I'll open a PR later adding those in.