Out and in docs

These docs aim to (minimalistically) describe how remotestorage.js works on the *out*side (e.g. how an app developer can use it), as well as on the *in*side (i.e. how the code works)
This isn't correct anymore, we don't have a node build, you install the `remotestoragejs` package via. npm and then you `var RemoteStorage = require('remotestoragejs')`. The `./node-main.js` file is the node bootstrap file that is called.