app/stories/speakers/edit_proposal.md
/events/:slug/proposals/:id/edit
As a speaker with a submitted proposal,
I want to see event information in the event info bar,
and a form to edit all areas of my proposal,
*except* for my user name and the user name and bio of other participating speakers,
followed by a 'Cancel' and 'Submit' button.
I also want to see a 'Preview' tab,
So that I may view my edited proposal in markdown as the reviewers will see it.