Update install.sh

[4cecoder]

https://unix.stackexchange.com/questions/8656/usr-bin-vs-usr-local-bin-on-linux

When I tried using install.sh on MacOS 12.3.1 it kept denying me access:

• to /usr/bin/ directly
  • I would have to disable MacOS's SIP for that to work

Instead: used a workaround

• to install to /usr/local/bin/
  • which also works fine on linux