Some more documentation

README.md

@@ -4,7 +4,7 @@ the power of npm.
 
 ## Installation
 ```sh
-npm i nibbler
+npm install nibbler
 ```
 
 ## Usage
@@ -28,21 +28,41 @@ If you want to run it against your local machine, simply run (given that your
 playbook file is named `playbook.js`):
 
 ```sh
+npm install nibbler-runner-local nibbler-apt nibbler-debian-iojs
 nibbler playbook.js
 ```
 
 If you desire to bootstrap a remote host (all actions happen through SSH, so no
 binaries are required on remote side):
 
 ```sh
+npm install nibbler-runner-ssh nibbler-apt nibbler-debian-iojs
 nibbler --runner ssh --ssh root@122.65.21.42 playbook.js
 ```
 
+### Useful helpers
+Nibbler comes with no "core modules". There are, however, numerous helpers you
+can use:
+
+* [`nibbler-exec`](https://www.npmjs.com/package/nibbler-exec) - for executing commands
+  with regard for global `sudo`
+* [`nibbler-apt`](https://www.npmjs.com/package/nibbler-apt) - for managing Apt packages
+* [`nibbler-copy`](https://www.npmjs.com/package/nibbler-copy) - for copying
+  local directories and files
+* [`nibbler-debian-iojs`](https://www.npmjs.com/package/nibbler-debian-iojs) -
+  for installing io.js on a Debian host
+
 ### Fancying up
 Handling arrays of directives isn't all that Nibbler can do. Underneath, it's
 all JavaScript, and Nibbler is specifically designed so that dropping down to
 it is as easy as it gets.
 
+If `module.exports` of your playbook is a function, Nibbler will call it with
+the context object and a callback. The context object looks as follows:
+
+* `runner` - a `child_process`-like API provided by your runner of choic
+* `sudo` - a `Boolean` indicating whether user requested global sudo
+
 ```js
 var async = require('async')
 var apt = require('nibbler-apt')