`make install`

[taahol]

We need make install and maybe some other standard targets too: https://www.gnu.org/software/make/manual/html_node/Standard-Targets.html

[Akuli]

I talked with @taahol about this. IMO we don't need a make install, because:

• it's easy enough to add the Jou directory to $PATH
• if hypothetically someone wanted to package Jou for a linux distro, that would already be possible e.g. like this: modify compiler/update.jou, put stdlib to /usr/lib/jou/stdlib, put compiler executable to /usr/lib/jou/jou, and add a symlink to /usr/bin.

But a better error message when running make install would be useful.