Refactor the introduction in README.

    ~'`~'`~'`~'`~

JsDuck aims to be a better documentation generator for [Ext JS][] than

the old [ext-doc][] was.

The standard way to give some structure to the JavaDoc-style code

documentation is to use HTML in doc-comments.  Although the resulting

documentation will look pretty, this is often achieved by sacrificing

the readability of comments - HTML can get quite ugly.

JsDuck does not like it.  Although it can handle comments written in

HTML, it prefers a friendlier [Markdown][] syntax:

    /**

     * Basic text field.  Can be used as a direct replacement for traditional

     * text inputs, or as the base class for more sophisticated input controls

     * (like Ext.form.TextArea and Ext.form.ComboBox).

     *

     * Validation

     * ----------

     *

     * The validation procedure is described in the documentation for

     * {@link #validateValue}.

     *

     * Alter Validation Behavior

     * -------------------------

     *

     * Validation behavior for each field can be configured:

     *

     * - `{@link Ext.form.TextField#invalidText invalidText}` :

     *   the default validation message to show if any validation step above

     *   does not provide a message when invalid

     * - `{@link Ext.form.TextField#maskRe maskRe}` :

     *   filter out keystrokes before any validation occurs

     * - `{@link Ext.form.TextField#stripCharsRe stripCharsRe}` :

     *   filter characters after being typed in, but before being validated

     *

     * @xtype textfield

     */

    Ext.define('Ext.form.field.Text', {

        extend: 'Ext.form.field.Base',

As you can see, JsDuck can infer several things from the code (like

`@class` and `@extends` in this case), so you don't have to repeat

yourself.

the old [ext-doc][] was. It is used by Sencha to generate the official

[Ext JS 4 documentation][ext4-docs].

The highlights of JSDuck are [Markdown][] support and keeping you DRY

by inferring a lot of information from code.  Read the [Guide][] for

full overview.

[Ext JS]: http://www.sencha.com/products/js/

[ext-doc]: http://ext-doc.org/

[Markdown]: http://daringfireball.net/projects/markdown/

[ext4-docs]: http://docs.sencha.com/ext-js/4-0/

[Guide]: https://github.com/senchalabs/jsduck/wiki/Guide

Getting it

Documenting your code

---------------------

For all the JSDuck supported see [Guide](https://github.com/senchalabs/jsduck/wiki/Guide) in wiki. 

All the supported syntax is described in the [Guide][]. 

Copying