documentation should also be accessible separately from demos

In addition to the combined demos+docs (with demos at the top, and documentation in tabs below), it should be possible to view and navigate documentation stand-alone. This could be at urls like

http://ui.jquery.com/docs/draggable

http://ui.jquery.com/docs/dialog#options

http://ui.jquery.com/docs/dialog#options-modal

http://ui.jquery.com/docs/sortable#methods-serialize

http://ui.jquery.com/docs/accordion#theming

This way you can

1. link directly to a docs page that doesn't have demos above it

2. link more directly to a section, such as options, methods, theming

3. link even more directly to the description (and demo) of a specific option or method. This won't work on demos+docs because a) the principal content is the demo, and b) we use #hashlinks to go to individual demos

4. View all the documentation for a plugin in one page (no tabs)

5. Print all the documentation for a plugin in one page (no tabs)