Add more documentation of lib usage

[lunelson]

The "lib" usage of harp seems to be pretty sparsely documented. In the main README it is mentioned that you can set up a Harp application like this

var harp = require("harp")
harp.server(projectPath [,args] [,callback])

... but no further information seems to exist about the args or the callback. Am I just looking in the wrong place?

[kennethormandy]

Here’s the docs page: http://harpjs.com/docs/environment/lib
We also have a PR which discusses some of the newer features: harp/harp.sh#56 I’ll get that merged soon

Let us know if that’s helpful. It’s possible the README just needs a review

[lunelson]

Thanks for those links; but both are mainly about using Harp as middleware with Express. It's mentioned only in passing, that there's a harp.server() method but in my testing it doesn't seem to work on its own: is it possible to fire up Harp from a script, without using Express? I basically just want the equivalent of the CLI command harp server but that I can run from inside of a larger script