Activate slide editing mode for example

We have this awesome editing mode for slide shows. We just don't enable 
it or tell anyone that it exists. Maybe we should do this.

This patch sets the type for the slide example.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

Author: SISheogorath

public/docs/slide-example.md

@@ -1,4 +1,5 @@
 ---
+type: slide
 slideOptions:
   transition: slide
 ---