Node installation instructions need to change for SIP on macOS

The Node instructions for macOS don't work with System Integrity Protection. The instruction try to create a symlink at /usr/bin, which is no longer available to us. The new location is /usr/loca/bin

Instead of:
sudo ln -s ~/.joplin-bin/bin/joplin /usr/bin/joplin

The documentation should say:
sudo ln -s ~/.joplin-bin/bin/joplin /usr/local/bin/joplin

This command is actually what's used for Linux too, so I'm wondering if the /user/local/bin directory is also present on most Linux distributions? If it is, I agree we could indeed change the command line.

Edit: ignore previous revision of this post

/usr/local/bin is a standard location.