design updates for idb / oec dashboard demo

[alexandersimoes]

Another iteration of the idb demo pages including the following feedback:

• keep the swirly background
• increase font-size (for further distances)
• make the country/product selections more of the focus for the intro page

[gabrielaperezponce]

@alexandersimoes Here is the updated file of this task in .sketch format
https://drive.google.com/open?id=1DDXNA_TTkyIIeBaBpAhHqv8fxR2j66T3