add install and basic usage to readme

README.md

@@ -3,4 +3,54 @@ DocAST
 
 [![Build Status](https://travis-ci.org/brettlangdon/docast.svg?branch=master)](https://travis-ci.org/brettlangdon/docast)
 
-Documentation generator for JS via AST parsing.
+DocAST is tool to help parse docs strings + additional properties from your
+javascript source code.
+
+## Install
+### NPM
+```bash
+npm install docast
+```
+
+### git
+```bash
+git clone git://github.com/brettlangdon/docast.git
+cd ./docast
+npm install
+```
+
+## Basic Usage
+The below example shows how you can use DocAST to parse documentation data from
+your javascript source code.
+
+### example.js
+```javascript
+/*
+ * This function is super cool and does all sorts of cool stuffs
+ */
+function some(cool, stuff){
+    if(typeof cool === undefined || typeof stuff === undefined){
+        throw new Exception('must provide "cool" or "stuff" parameter');
+    }
+
+    if(cool > stuff){
+        return stuff;
+    } else if(stuff > cool){
+        return cool;
+    } else {
+        return null;
+    };
+}
+```
+
+### Usage
+```javascript
+var docast = require('docast');
+var comments = docast.parse('./example.js');
+// this is the result
+comments = [ { name: 'some',
+               params: [ 'cool', 'stuff' ],
+               returns: [ 'stuff', 'cool', null ],
+               raises: [ 'Exception' ],
+               doc: ' This function is super cool and does all sorts of cool stuffs\n ' } ]
+```