Added story submission guidelines to the edit page.

After submitting a story, I wanted to edit it and add a link to the "Text" box but I wasn't sure if it was within the guidelines so I had to open "Submit Story" in a new tab to read them.

When I copied over the guidelines code from `new.html.erb` to `edit.html.erb` I noticed there were two `<li>` elements that weren't properly ended and the formatting was weird. I wasn't sure if this was intentional or not but I cleaned it up in both files.