Please don't require fnm to have all the variables at once. #1470
Description
I don't use fnm and nodejs all the time, but occasionally. Thus polluting environment and spend some time to run an app just to set variables I won't use is quite wasteful. More so, it creates a symlink to a default environment, which is not cleaned afterwards (#696).
Even fnm is written in Rust, it does quite a lot of work before it exists.
I'd like to set minimal variable list and run fnm only demand. nvm provided me such ability and I prefer to keep it here as well.