update urbit binary

pull-update.sh

#! /bin/bash

# this depends on the trash command, see how-not-to-rm-yourself by sindresorhus at https://github.com/sindresorhus/guides/blob/main/how-not-to-rm-yourself.md
# tl;dr on mac: brew install trash

# why not just use rm? because trash can be undone

trash urbit
trash urbit-worker
trash urbit-king
trash darwin.tgz
curl -JLO https://urbit.org/install/mac/latest # see https://urbit.org/using/install/
tar zxvf ./darwin.tgz --strip=1

# to create the file: touch pull-update.sh
# paste all of this into the file
# to make executable: chmod +x 
# to execute: ./pull-update.sh