install.sh should install to ~/.local/bin/ by default

[0cjs]

Given that everything opam does is stored in the user's home dir (which is part of the point of it), there's no good reason that the default location for the binary itself should not be in the user's home dir as well, and doing this would avoid needing to sudo.

~/.local/bin/ has long been the standard location for things like this, though it's reasonable to consider backup locations (such as ~/bin/) as well.

Whether a location is reasonable or not could be determined by checking to see if it both exists and is in the path before suggesting it as the default.

[dra27]

Related to #3962