Please clarify the docs regarding when dev/prod modes are on (Node)

Hello,

perhaps it wasn't my brightest day :-) but I found it difficult to find out when the dev or prod modes are active under Node.js. It would be great clarify that in the docs.

I believe this is true (and exhaustive) but am not sure:

/*1.*/ var Immutable = require('seamless-immutable'); // => dev mode
/*2.*/ var Immutable = require('seamless-immutable/seamless-immutable.production.min'); // => prod mode
/*3.*/ var Immutable = require('seamless-immutable/seamless-immutable.production.min'); process.env.NODE_ENV = "development"; // => dev mode

Thank you!