Showing only an excerpt in the Wiki archive page

Hi

Is it possible to only display an excerpt of the wiki article inside the archive wiki page? Kinda like in here: http://hitchhikerteaguide.org/guide/
http://bit.ly/1NWVwjX

I also like to have the 'create new' button in the archive page rather than inside some article.
What's the reason to add that button there?

Thanks!