Make the readme less note-y, and more document-y

I think it's easier to work on once there's some semblance of a document structure to these notes.
A better title
Details about talks (content, scheduling) [#3]
Add timing info and notes about projected content [#3]
Add some stuff about sponsoring [#3, #6]

Left prices off as I think they might be a bit changeable.
Fix markdown for numbered lists
Merge pull request #7 from lrug/less-notes-more-document

Make the readme less note-y, and more document-y