Demodocs: add data

Not sure this is the best place to put this. I am also not sure what it does.

See #90

Author: Blendify

demo_docs/source/index.rst

@@ -320,7 +320,14 @@ Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac tu
 Aenean nec tincidunt odio. Nam ex quam, egestas ut nisi eu, interdum commodo arcu.
 Mauris venenatis nisi eu condimentum tincidunt. Maecenas eu odio eleifend, fermentum turpis sit amet, faucibus ex.
 
+Data
+====
 
+.. data:: Data_item_1
+          Data_item_2
+          Data_item_3
+
+Some data link:data:`Data_item_1`.
 
 Download links
 ==============