3.0 Start new ORM documentation

Start filling in the ORM docs skeleton. I've started with the configuration, and connection objects.

I'm wondering if the method directives will interrupt the reader's flow given the more narrative nature of these docs. I didn't want to lose the ability to directly link to documentation relevant to specific classes/methods, so I've included them. One option is to update the CSS and make the class/method sections more visually subtle.