Clarify nvm example or swap it for a more recognizable one.

[jdalton]

In the what about section there's an nvm example. It's not clear to me how nvm loads js files. I use it to switch node versions. Maybe a better example could be used.

[caridy]

IIRC, this is a reference to some previous conversation where people were asking about how other languages/programs (e.g.: shell program) will identify the mode of the file, and the point made is that if you need to identify the mode, it is very likely that you have JSON support.