Moved most of currente README into Github wiki.

* RSpec

List of supported @tags

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

More

----

* @class

* @extends

* @singleton

* @cfg

* @constructor

* @property

* @type

* @method

* @event

* @param

* @return alias @returns

* @static

* @xtype

* @member

* {@link}

* [List of supported @tags][tags]

* [List of doc-comment errors(?) found in ExtJS source][errors]

* @ignore, @hide, @private, @protected - in JsDuck implementation

  @ignore, @hide and @protected are considered aliases for @private.

  (Some usage stats from ExtJS source: @hide 306 times, @private 199

  times, @ignore 11 times.)

Unsupported:

* @namespace - Looks useless to me and indeed ExtJS source doesn't use

  it at all.

Some links:

* [ext-doc @tags](http://code.google.com/p/ext-doc/wiki/TagSpecification)

* [jsdoc-toolkit @tags](http://code.google.com/p/jsdoc-toolkit/wiki/TagReference)

List of doc-comment errors(?) found in ExtJS source

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

The file `src/core/Error.js` documents `Ext.handleError` method. But

that doc-comment doesn't follow a @class definition, nor does it

contain @member, nor is it marked with @private, @hide, or @ignore.

Therefore this method is simply not included in official ExtJS

documentation.

The file `src/ext-core/src/core/Ext.js` has a doc-comment that says

"Removes a DOM node from the document." but it contains no @tags and

is followed by another doc-comment.  The result is that official ExtJS

documentation simply lists a nameless property of `Ext` class.

For some reason `@see` is only used inside normal comments, not in

doc-comments.  There are only 7 of these though.

Two uses of `@member` also name the item itself.  For example `@member

Ext apply` - although that's pretty much useless as that is followed

by code from which we can infer that the name should be `apply` plus

it's preceded by `@class Ext` so a member declaration shouldn't be

needed at all.  The other example is `@member Ext.Element

getTextWidth`, again followed by code that says the same thing.  Given

this silliness, JsDuck currently only supports the form `@member

ClassName`.

[tags]: https://github.com/nene/jsduck/wiki/List-of-supported-@tags

[errors]: https://github.com/nene/jsduck/wiki/List-of-doc-comment-errors(%3F)-found-in-ExtJS-source