Branch/get duck ready for main page

I plan to embed the duck app on the VWF main page, but I need to change two things first:
1. Make sure that visitors don't accidentally scroll into the duck when they try to scroll down the page (so I made `navmode` set to `none`
2. Get rid of the unsightly scrollbars that show up (so I removed the editor)

There's some miscellaneous cleanup in there, too, to remove unneeded lines so it's a clearer example app (still more to do there, but not in this pull request).

@davideaster or @scottnc27603 would you mind reviewing?