[wp-docs] Codex addition: WP Gallery Overview

[Michael Hancock]

>>>
esmi at quirm dot net

Can we add:

<http://codex.wordpress.org/User:Esmi/The_WordPress_Gallery>

to the main Codex?

Reasoning: a lot of users still get confused about how the gallery (and
especially the creation of the image attachments) works.
<<<

Done.  New location is http://codex.wordpress.org/The_WordPress_Gallery

I also added two categories.  

MichaelH