doc: no Node.js(1)

Node.js(1) does not make sense.
Node(1) would, but this isn’t a `man` page.

PR-URL: https://github.com/nodejs/node/pull/6167


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Robert Jefe Lindstädt <robert.lindstaedt@gmail.com>